From c30d9fc82423a58096673d9960c312425ffd5652 Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Wed, 23 Sep 2026 19:24:09 +0000
Subject: [PATCH 1/3] fix(generator): emit lint-clean GAPIC output

Add missing returns in generated close() paths, chain .catch on the
Locations mixin callback test (matching the IAM/operations sites), and
use const for routingParameter. Fixes #9432.
---
 .../src/v1/asset_service_client.ts.baseline   |  1 +
 .../test/gapic_asset_service_v1.ts.baseline   |  2 ++
 .../src/v1/asset_service_client.ts.baseline   |  1 +
 .../test/gapic_asset_service_v1.ts.baseline   |  2 ++
 .../big_query_storage_client.ts.baseline      |  1 +
 ...apic_big_query_storage_v1beta1.ts.baseline |  2 ++
 .../big_query_storage_client.ts.baseline      |  1 +
 ...apic_big_query_storage_v1beta1.ts.baseline |  2 ++
 .../src/v2/dataset_service_client.ts.baseline |  1 +
 .../esm/src/v2/job_service_client.ts.baseline |  1 +
 .../src/v2/model_service_client.ts.baseline   |  1 +
 .../src/v2/project_service_client.ts.baseline |  1 +
 .../src/v2/routine_service_client.ts.baseline |  1 +
 ...w_access_policy_service_client.ts.baseline |  1 +
 .../src/v2/table_service_client.ts.baseline   |  1 +
 .../test/gapic_dataset_service_v2.ts.baseline |  2 ++
 .../esm/test/gapic_job_service_v2.ts.baseline |  2 ++
 .../test/gapic_model_service_v2.ts.baseline   |  2 ++
 .../test/gapic_project_service_v2.ts.baseline |  2 ++
 .../test/gapic_routine_service_v2.ts.baseline |  2 ++
 ...c_row_access_policy_service_v2.ts.baseline |  2 ++
 .../test/gapic_table_service_v2.ts.baseline   |  2 ++
 .../src/v2/dataset_service_client.ts.baseline |  1 +
 .../src/v2/job_service_client.ts.baseline     |  1 +
 .../src/v2/model_service_client.ts.baseline   |  1 +
 .../src/v2/project_service_client.ts.baseline |  1 +
 .../src/v2/routine_service_client.ts.baseline |  1 +
 ...w_access_policy_service_client.ts.baseline |  1 +
 .../src/v2/table_service_client.ts.baseline   |  1 +
 .../test/gapic_dataset_service_v2.ts.baseline |  2 ++
 .../test/gapic_job_service_v2.ts.baseline     |  2 ++
 .../test/gapic_model_service_v2.ts.baseline   |  2 ++
 .../test/gapic_project_service_v2.ts.baseline |  2 ++
 .../test/gapic_routine_service_v2.ts.baseline |  2 ++
 ...c_row_access_policy_service_v2.ts.baseline |  2 ++
 .../test/gapic_table_service_v2.ts.baseline   |  2 ++
 .../esm/src/v1/addresses_client.ts.baseline   |  1 +
 .../v1/region_operations_client.ts.baseline   |  1 +
 .../esm/test/gapic_addresses_v1.ts.baseline   |  2 ++
 .../gapic_region_operations_v1.ts.baseline    |  2 ++
 .../src/v1/addresses_client.ts.baseline       |  1 +
 .../v1/region_operations_client.ts.baseline   |  1 +
 .../test/gapic_addresses_v1.ts.baseline       |  2 ++
 .../gapic_region_operations_v1.ts.baseline    |  2 ++
 .../v1/deprecated_service_client.ts.baseline  |  1 +
 .../v1/deprecated_service_client.ts.baseline  |  1 +
 .../src/v1beta1/compliance_client.ts.baseline |  1 +
 .../esm/src/v1beta1/echo_client.ts.baseline   |  3 +-
 .../src/v1beta1/identity_client.ts.baseline   |  1 +
 .../src/v1beta1/messaging_client.ts.baseline  |  1 +
 .../sequence_service_client.ts.baseline       |  1 +
 .../src/v1beta1/testing_client.ts.baseline    |  1 +
 .../test/gapic_compliance_v1beta1.ts.baseline |  2 ++
 .../esm/test/gapic_echo_v1beta1.ts.baseline   |  2 ++
 .../test/gapic_identity_v1beta1.ts.baseline   |  2 ++
 .../test/gapic_messaging_v1beta1.ts.baseline  |  2 ++
 ...gapic_sequence_service_v1beta1.ts.baseline |  2 ++
 .../test/gapic_testing_v1beta1.ts.baseline    |  2 ++
 .../src/v1beta1/compliance_client.ts.baseline |  1 +
 .../src/v1beta1/echo_client.ts.baseline       |  3 +-
 .../src/v1beta1/identity_client.ts.baseline   |  1 +
 .../src/v1beta1/messaging_client.ts.baseline  |  1 +
 .../sequence_service_client.ts.baseline       |  1 +
 .../src/v1beta1/testing_client.ts.baseline    |  1 +
 .../test/gapic_compliance_v1beta1.ts.baseline |  2 ++
 .../test/gapic_echo_v1beta1.ts.baseline       |  2 ++
 .../test/gapic_identity_v1beta1.ts.baseline   |  2 ++
 .../test/gapic_messaging_v1beta1.ts.baseline  |  2 ++
 ...gapic_sequence_service_v1beta1.ts.baseline |  2 ++
 .../test/gapic_testing_v1beta1.ts.baseline    |  2 ++
 .../esm/src/v2/dlp_service_client.ts.baseline |  1 +
 .../esm/test/gapic_dlp_service_v2.ts.baseline |  2 ++
 .../dlp/src/v2/dlp_service_client.ts.baseline |  1 +
 .../dlp/test/gapic_dlp_service_v2.ts.baseline |  2 ++
 ...te_methods_test_service_client.ts.baseline |  1 +
 ...licate_methods_test_service_v1.ts.baseline | 34 +++++++++++--------
 ...te_methods_test_service_client.ts.baseline |  1 +
 ...licate_methods_test_service_v1.ts.baseline | 34 +++++++++++--------
 .../key_management_service_client.ts.baseline |  1 +
 ...apic_key_management_service_v1.ts.baseline |  2 ++
 .../key_management_service_client.ts.baseline |  1 +
 ...apic_key_management_service_v1.ts.baseline |  2 ++
 .../v2/config_service_v2_client.ts.baseline   |  1 +
 .../v2/logging_service_v2_client.ts.baseline  |  1 +
 .../v2/metrics_service_v2_client.ts.baseline  |  1 +
 .../gapic_config_service_v2_v2.ts.baseline    |  2 ++
 .../gapic_logging_service_v2_v2.ts.baseline   |  2 ++
 .../gapic_metrics_service_v2_v2.ts.baseline   |  2 ++
 .../v2/config_service_v2_client.ts.baseline   |  1 +
 .../v2/logging_service_v2_client.ts.baseline  |  1 +
 .../v2/metrics_service_v2_client.ts.baseline  |  1 +
 .../gapic_config_service_v2_v2.ts.baseline    |  2 ++
 .../gapic_logging_service_v2_v2.ts.baseline   |  2 ++
 .../gapic_metrics_service_v2_v2.ts.baseline   |  2 ++
 .../alert_policy_service_client.ts.baseline   |  1 +
 .../src/v3/group_service_client.ts.baseline   |  1 +
 .../src/v3/metric_service_client.ts.baseline  |  1 +
 ...ication_channel_service_client.ts.baseline |  1 +
 ...vice_monitoring_service_client.ts.baseline |  1 +
 .../uptime_check_service_client.ts.baseline   |  1 +
 .../gapic_alert_policy_service_v3.ts.baseline |  2 ++
 .../test/gapic_group_service_v3.ts.baseline   |  2 ++
 .../test/gapic_metric_service_v3.ts.baseline  |  2 ++
 ...otification_channel_service_v3.ts.baseline |  2 ++
 ..._service_monitoring_service_v3.ts.baseline |  2 ++
 .../gapic_uptime_check_service_v3.ts.baseline |  2 ++
 .../alert_policy_service_client.ts.baseline   |  1 +
 .../src/v3/group_service_client.ts.baseline   |  1 +
 .../src/v3/metric_service_client.ts.baseline  |  1 +
 ...ication_channel_service_client.ts.baseline |  1 +
 ...vice_monitoring_service_client.ts.baseline |  1 +
 .../uptime_check_service_client.ts.baseline   |  1 +
 .../gapic_alert_policy_service_v3.ts.baseline |  2 ++
 .../test/gapic_group_service_v3.ts.baseline   |  2 ++
 .../test/gapic_metric_service_v3.ts.baseline  |  2 ++
 ...otification_channel_service_v3.ts.baseline |  2 ++
 ..._service_monitoring_service_v3.ts.baseline |  2 ++
 .../gapic_uptime_check_service_v3.ts.baseline |  2 ++
 .../esm/src/v1beta1/naming_client.ts.baseline |  1 +
 .../esm/test/gapic_naming_v1beta1.ts.baseline |  2 ++
 .../src/v1beta1/naming_client.ts.baseline     |  1 +
 .../test/gapic_naming_v1beta1.ts.baseline     |  2 ++
 .../v1beta1/cloud_redis_client.ts.baseline    |  1 +
 .../gapic_cloud_redis_v1beta1.ts.baseline     |  2 ++
 .../v1beta1/cloud_redis_client.ts.baseline    |  1 +
 .../gapic_cloud_redis_v1beta1.ts.baseline     |  2 ++
 .../analytics_service_client.ts.baseline      |  1 +
 .../v2alpha/branch_service_client.ts.baseline |  1 +
 .../catalog_service_client.ts.baseline        |  1 +
 .../completion_service_client.ts.baseline     |  1 +
 .../control_service_client.ts.baseline        |  1 +
 ...sational_search_service_client.ts.baseline |  1 +
 ...rative_question_service_client.ts.baseline |  1 +
 ...er_account_link_service_client.ts.baseline |  1 +
 .../v2alpha/model_service_client.ts.baseline  |  1 +
 .../prediction_service_client.ts.baseline     |  1 +
 .../product_service_client.ts.baseline        |  1 +
 .../project_service_client.ts.baseline        |  1 +
 .../v2alpha/search_service_client.ts.baseline |  1 +
 .../serving_config_service_client.ts.baseline |  1 +
 .../user_event_service_client.ts.baseline     |  1 +
 ...apic_analytics_service_v2alpha.ts.baseline |  2 ++
 .../gapic_branch_service_v2alpha.ts.baseline  |  2 ++
 .../gapic_catalog_service_v2alpha.ts.baseline |  2 ++
 ...pic_completion_service_v2alpha.ts.baseline |  2 ++
 .../gapic_control_service_v2alpha.ts.baseline |  2 ++
 ...ational_search_service_v2alpha.ts.baseline |  2 ++
 ...ative_question_service_v2alpha.ts.baseline |  2 ++
 ...r_account_link_service_v2alpha.ts.baseline |  2 ++
 .../gapic_model_service_v2alpha.ts.baseline   |  2 ++
 ...pic_prediction_service_v2alpha.ts.baseline |  2 ++
 .../gapic_product_service_v2alpha.ts.baseline |  2 ++
 .../gapic_project_service_v2alpha.ts.baseline |  2 ++
 .../gapic_search_service_v2alpha.ts.baseline  |  2 ++
 ...serving_config_service_v2alpha.ts.baseline |  2 ++
 ...pic_user_event_service_v2alpha.ts.baseline |  2 ++
 .../analytics_service_client.ts.baseline      |  1 +
 .../v2alpha/branch_service_client.ts.baseline |  1 +
 .../catalog_service_client.ts.baseline        |  1 +
 .../completion_service_client.ts.baseline     |  1 +
 .../control_service_client.ts.baseline        |  1 +
 ...sational_search_service_client.ts.baseline |  1 +
 ...rative_question_service_client.ts.baseline |  1 +
 ...er_account_link_service_client.ts.baseline |  1 +
 .../v2alpha/model_service_client.ts.baseline  |  1 +
 .../prediction_service_client.ts.baseline     |  1 +
 .../product_service_client.ts.baseline        |  1 +
 .../project_service_client.ts.baseline        |  1 +
 .../v2alpha/search_service_client.ts.baseline |  1 +
 .../serving_config_service_client.ts.baseline |  1 +
 .../user_event_service_client.ts.baseline     |  1 +
 ...apic_analytics_service_v2alpha.ts.baseline |  2 ++
 .../gapic_branch_service_v2alpha.ts.baseline  |  2 ++
 .../gapic_catalog_service_v2alpha.ts.baseline |  2 ++
 ...pic_completion_service_v2alpha.ts.baseline |  2 ++
 .../gapic_control_service_v2alpha.ts.baseline |  2 ++
 ...ational_search_service_v2alpha.ts.baseline |  2 ++
 ...ative_question_service_v2alpha.ts.baseline |  2 ++
 ...r_account_link_service_v2alpha.ts.baseline |  2 ++
 .../gapic_model_service_v2alpha.ts.baseline   |  2 ++
 ...pic_prediction_service_v2alpha.ts.baseline |  2 ++
 .../gapic_product_service_v2alpha.ts.baseline |  2 ++
 .../gapic_project_service_v2alpha.ts.baseline |  2 ++
 .../gapic_search_service_v2alpha.ts.baseline  |  2 ++
 ...serving_config_service_v2alpha.ts.baseline |  2 ++
 ...pic_user_event_service_v2alpha.ts.baseline |  2 ++
 .../src/v1/test_service_client.ts.baseline    |  7 ++--
 .../test/gapic_test_service_v1.ts.baseline    |  2 ++
 .../src/v1/test_service_client.ts.baseline    |  7 ++--
 .../test/gapic_test_service_v1.ts.baseline    |  2 ++
 .../src/v1beta1/compliance_client.ts.baseline |  1 +
 .../esm/src/v1beta1/echo_client.ts.baseline   |  3 +-
 .../src/v1beta1/identity_client.ts.baseline   |  1 +
 .../src/v1beta1/messaging_client.ts.baseline  |  1 +
 .../sequence_service_client.ts.baseline       |  1 +
 .../src/v1beta1/testing_client.ts.baseline    |  1 +
 .../test/gapic_compliance_v1beta1.ts.baseline |  2 ++
 .../esm/test/gapic_echo_v1beta1.ts.baseline   |  2 ++
 .../test/gapic_identity_v1beta1.ts.baseline   |  2 ++
 .../test/gapic_messaging_v1beta1.ts.baseline  |  2 ++
 ...gapic_sequence_service_v1beta1.ts.baseline |  2 ++
 .../test/gapic_testing_v1beta1.ts.baseline    |  2 ++
 .../esm/src/v1beta1/echo_client.ts.baseline   |  3 +-
 .../esm/test/gapic_echo_v1beta1.ts.baseline   |  2 ++
 .../src/v1beta1/echo_client.ts.baseline       |  3 +-
 .../test/gapic_echo_v1beta1.ts.baseline       |  2 ++
 .../src/v1beta1/compliance_client.ts.baseline |  1 +
 .../src/v1beta1/echo_client.ts.baseline       |  3 +-
 .../src/v1beta1/identity_client.ts.baseline   |  1 +
 .../src/v1beta1/messaging_client.ts.baseline  |  1 +
 .../sequence_service_client.ts.baseline       |  1 +
 .../src/v1beta1/testing_client.ts.baseline    |  1 +
 .../test/gapic_compliance_v1beta1.ts.baseline |  2 ++
 .../test/gapic_echo_v1beta1.ts.baseline       |  2 ++
 .../test/gapic_identity_v1beta1.ts.baseline   |  2 ++
 .../test/gapic_messaging_v1beta1.ts.baseline  |  2 ++
 ...gapic_sequence_service_v1beta1.ts.baseline |  2 ++
 .../test/gapic_testing_v1beta1.ts.baseline    |  2 ++
 .../esm/src/v2/cloud_tasks_client.ts.baseline |  1 +
 .../esm/test/gapic_cloud_tasks_v2.ts.baseline |  2 ++
 .../src/v2/cloud_tasks_client.ts.baseline     |  1 +
 .../test/gapic_cloud_tasks_v2.ts.baseline     |  2 ++
 .../src/v1/text_to_speech_client.ts.baseline  |  1 +
 .../test/gapic_text_to_speech_v1.ts.baseline  |  2 ++
 .../src/v1/text_to_speech_client.ts.baseline  |  1 +
 .../test/gapic_text_to_speech_v1.ts.baseline  |  2 ++
 .../translation_service_client.ts.baseline    |  1 +
 ...ic_translation_service_v3beta1.ts.baseline |  2 ++
 .../translation_service_client.ts.baseline    |  1 +
 ...ic_translation_service_v3beta1.ts.baseline |  2 ++
 ...eo_intelligence_service_client.ts.baseline |  1 +
 ..._video_intelligence_service_v1.ts.baseline |  2 ++
 ...eo_intelligence_service_client.ts.baseline |  1 +
 ..._video_intelligence_service_v1.ts.baseline |  2 ++
 .../templates/cjs/typescript_gapic/_util.njk  |  2 +-
 .../src/$version/$service_client.ts.njk       |  1 +
 .../test/gapic_$service_$version.ts.njk       |  4 ++-
 .../templates/esm/typescript_gapic/_util.njk  |  2 +-
 .../esm/src/$version/$service_client.ts.njk   |  1 +
 .../esm/test/gapic_$service_$version.ts.njk   |  4 ++-
 240 files changed, 408 insertions(+), 44 deletions(-)

diff --git a/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/src/v1/asset_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/src/v1/asset_service_client.ts.baseline
index 92269d00bf81..0ca9e0673e70 100644
--- a/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/src/v1/asset_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/src/v1/asset_service_client.ts.baseline
@@ -1575,6 +1575,7 @@ export class AssetServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/test/gapic_asset_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/test/gapic_asset_service_v1.ts.baseline
index 4857a68c71ba..9cde74ade06a 100644
--- a/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/test/gapic_asset_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/test/gapic_asset_service_v1.ts.baseline
@@ -240,6 +240,7 @@ describe('v1.AssetServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -256,6 +257,7 @@ describe('v1.AssetServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/asset/src/v1/asset_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/asset/src/v1/asset_service_client.ts.baseline
index 5b75c05c905f..f499600b58eb 100644
--- a/core/generator/gapic-generator-typescript/baselines/asset/src/v1/asset_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/asset/src/v1/asset_service_client.ts.baseline
@@ -1553,6 +1553,7 @@ export class AssetServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/asset/test/gapic_asset_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/asset/test/gapic_asset_service_v1.ts.baseline
index d16a2b86397e..b61105b1e90a 100644
--- a/core/generator/gapic-generator-typescript/baselines/asset/test/gapic_asset_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/asset/test/gapic_asset_service_v1.ts.baseline
@@ -229,6 +229,7 @@ describe('v1.AssetServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -245,6 +246,7 @@ describe('v1.AssetServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/src/v1beta1/big_query_storage_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/src/v1beta1/big_query_storage_client.ts.baseline
index c00949cabdf7..7d1dbd0fffe0 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/src/v1beta1/big_query_storage_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/src/v1beta1/big_query_storage_client.ts.baseline
@@ -1235,6 +1235,7 @@ export class BigQueryStorageClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/test/gapic_big_query_storage_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/test/gapic_big_query_storage_v1beta1.ts.baseline
index 7c869a0797e8..06bc214cd8a9 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/test/gapic_big_query_storage_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/test/gapic_big_query_storage_v1beta1.ts.baseline
@@ -236,6 +236,7 @@ describe('v1beta1.BigQueryStorageClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -252,6 +253,7 @@ describe('v1beta1.BigQueryStorageClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-storage/src/v1beta1/big_query_storage_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-storage/src/v1beta1/big_query_storage_client.ts.baseline
index 3bd77dc1b743..85cfb987f9a0 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-storage/src/v1beta1/big_query_storage_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-storage/src/v1beta1/big_query_storage_client.ts.baseline
@@ -1213,6 +1213,7 @@ export class BigQueryStorageClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-storage/test/gapic_big_query_storage_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-storage/test/gapic_big_query_storage_v1beta1.ts.baseline
index eb4eca1f2ff3..c2d8f16f7845 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-storage/test/gapic_big_query_storage_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-storage/test/gapic_big_query_storage_v1beta1.ts.baseline
@@ -225,6 +225,7 @@ describe('v1beta1.BigQueryStorageClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -241,6 +242,7 @@ describe('v1beta1.BigQueryStorageClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/dataset_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/dataset_service_client.ts.baseline
index 2712ed52f2cc..bdf5ebb27a49 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/dataset_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/dataset_service_client.ts.baseline
@@ -1503,6 +1503,7 @@ export class DatasetServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/job_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/job_service_client.ts.baseline
index cbb812f9cd0b..f2f8eaff5add 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/job_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/job_service_client.ts.baseline
@@ -1542,6 +1542,7 @@ export class JobServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/model_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/model_service_client.ts.baseline
index 5969ff49c8d3..c8ab55ae0f72 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/model_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/model_service_client.ts.baseline
@@ -1050,6 +1050,7 @@ export class ModelServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/project_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/project_service_client.ts.baseline
index bfe2d95fbf15..9d5de0ffa3eb 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/project_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/project_service_client.ts.baseline
@@ -532,6 +532,7 @@ export class ProjectServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/routine_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/routine_service_client.ts.baseline
index 0bd9e66f53f3..3d6976a59893 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/routine_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/routine_service_client.ts.baseline
@@ -1335,6 +1335,7 @@ export class RoutineServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/row_access_policy_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/row_access_policy_service_client.ts.baseline
index 1319960c1085..b3ed1ea8a840 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/row_access_policy_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/row_access_policy_service_client.ts.baseline
@@ -653,6 +653,7 @@ export class RowAccessPolicyServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/table_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/table_service_client.ts.baseline
index ecef20be8f13..75baafad231a 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/table_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/src/v2/table_service_client.ts.baseline
@@ -1359,6 +1359,7 @@ export class TableServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_dataset_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_dataset_service_v2.ts.baseline
index a77197c28906..76fb44a02b4f 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_dataset_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_dataset_service_v2.ts.baseline
@@ -271,6 +271,7 @@ describe('v2.DatasetServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -287,6 +288,7 @@ describe('v2.DatasetServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_job_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_job_service_v2.ts.baseline
index ddf73439cc49..f35baebe0fcd 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_job_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_job_service_v2.ts.baseline
@@ -269,6 +269,7 @@ describe('v2.JobServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -285,6 +286,7 @@ describe('v2.JobServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_model_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_model_service_v2.ts.baseline
index 2c8e3d22ddeb..7cd2817eb91d 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_model_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_model_service_v2.ts.baseline
@@ -271,6 +271,7 @@ describe('v2.ModelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -287,6 +288,7 @@ describe('v2.ModelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_project_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_project_service_v2.ts.baseline
index c94b19356714..a4debcaad21d 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_project_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_project_service_v2.ts.baseline
@@ -208,6 +208,7 @@ describe('v2.ProjectServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -224,6 +225,7 @@ describe('v2.ProjectServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_routine_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_routine_service_v2.ts.baseline
index 2bd0303d56c0..a05af52ba6bf 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_routine_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_routine_service_v2.ts.baseline
@@ -271,6 +271,7 @@ describe('v2.RoutineServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -287,6 +288,7 @@ describe('v2.RoutineServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_row_access_policy_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_row_access_policy_service_v2.ts.baseline
index b97233a55176..78296d01919d 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_row_access_policy_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_row_access_policy_service_v2.ts.baseline
@@ -284,6 +284,7 @@ describe('v2.RowAccessPolicyServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -301,6 +302,7 @@ describe('v2.RowAccessPolicyServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_table_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_table_service_v2.ts.baseline
index f0da48c7f653..020f9414d188 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_table_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_table_service_v2.ts.baseline
@@ -271,6 +271,7 @@ describe('v2.TableServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -287,6 +288,7 @@ describe('v2.TableServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/dataset_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/dataset_service_client.ts.baseline
index eef119e41c64..426dc28661de 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/dataset_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/dataset_service_client.ts.baseline
@@ -1481,6 +1481,7 @@ export class DatasetServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/job_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/job_service_client.ts.baseline
index 1cea19576ffc..93cd56d2d30b 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/job_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/job_service_client.ts.baseline
@@ -1520,6 +1520,7 @@ export class JobServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/model_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/model_service_client.ts.baseline
index 8750b9447c6a..12dffe93512b 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/model_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/model_service_client.ts.baseline
@@ -1028,6 +1028,7 @@ export class ModelServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/project_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/project_service_client.ts.baseline
index c5991a75afce..a03bf995d937 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/project_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/project_service_client.ts.baseline
@@ -510,6 +510,7 @@ export class ProjectServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/routine_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/routine_service_client.ts.baseline
index 48d2a07f22bf..cc6da95b421c 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/routine_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/routine_service_client.ts.baseline
@@ -1313,6 +1313,7 @@ export class RoutineServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/row_access_policy_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/row_access_policy_service_client.ts.baseline
index add1548c9ff2..cf1ba2d9a184 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/row_access_policy_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/row_access_policy_service_client.ts.baseline
@@ -631,6 +631,7 @@ export class RowAccessPolicyServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/table_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/table_service_client.ts.baseline
index 7d24b2968537..0b7946c7cea4 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/table_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/src/v2/table_service_client.ts.baseline
@@ -1337,6 +1337,7 @@ export class TableServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_dataset_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_dataset_service_v2.ts.baseline
index 6036fef34019..2b3eaeb6e759 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_dataset_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_dataset_service_v2.ts.baseline
@@ -260,6 +260,7 @@ describe('v2.DatasetServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -276,6 +277,7 @@ describe('v2.DatasetServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_job_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_job_service_v2.ts.baseline
index 66743a3a20c8..c4fc31d5dec6 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_job_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_job_service_v2.ts.baseline
@@ -258,6 +258,7 @@ describe('v2.JobServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -274,6 +275,7 @@ describe('v2.JobServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_model_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_model_service_v2.ts.baseline
index 9acdff67c89f..ceee71b9a639 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_model_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_model_service_v2.ts.baseline
@@ -260,6 +260,7 @@ describe('v2.ModelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -276,6 +277,7 @@ describe('v2.ModelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_project_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_project_service_v2.ts.baseline
index b9e3b31f074f..d5b74accb4c5 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_project_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_project_service_v2.ts.baseline
@@ -197,6 +197,7 @@ describe('v2.ProjectServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -213,6 +214,7 @@ describe('v2.ProjectServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_routine_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_routine_service_v2.ts.baseline
index a0061d7a81a1..efa6c8983dba 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_routine_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_routine_service_v2.ts.baseline
@@ -260,6 +260,7 @@ describe('v2.RoutineServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -276,6 +277,7 @@ describe('v2.RoutineServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_row_access_policy_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_row_access_policy_service_v2.ts.baseline
index 057a2a620d47..69a60627fab3 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_row_access_policy_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_row_access_policy_service_v2.ts.baseline
@@ -273,6 +273,7 @@ describe('v2.RowAccessPolicyServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -290,6 +291,7 @@ describe('v2.RowAccessPolicyServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_table_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_table_service_v2.ts.baseline
index 80e3a13727cb..5e3bf93ef666 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_table_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_table_service_v2.ts.baseline
@@ -260,6 +260,7 @@ describe('v2.TableServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -276,6 +277,7 @@ describe('v2.TableServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/src/v1/addresses_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/src/v1/addresses_client.ts.baseline
index cc3be0b8c5ad..db3bbfe0419f 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/src/v1/addresses_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/src/v1/addresses_client.ts.baseline
@@ -1049,6 +1049,7 @@ export class AddressesClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/src/v1/region_operations_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/src/v1/region_operations_client.ts.baseline
index 47a1cd66449d..d853b30bfdc0 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/src/v1/region_operations_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/src/v1/region_operations_client.ts.baseline
@@ -684,6 +684,7 @@ export class RegionOperationsClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_addresses_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_addresses_v1.ts.baseline
index cd48c4c40ab5..b950ca904db8 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_addresses_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_addresses_v1.ts.baseline
@@ -282,6 +282,7 @@ describe('v1.AddressesClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -298,6 +299,7 @@ describe('v1.AddressesClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_region_operations_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_region_operations_v1.ts.baseline
index 8790d8899295..e799b69a5d0c 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_region_operations_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_region_operations_v1.ts.baseline
@@ -221,6 +221,7 @@ describe('v1.RegionOperationsClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -237,6 +238,7 @@ describe('v1.RegionOperationsClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/compute/src/v1/addresses_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute/src/v1/addresses_client.ts.baseline
index 232e874ad8e0..4ffec6069d7e 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute/src/v1/addresses_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute/src/v1/addresses_client.ts.baseline
@@ -1033,6 +1033,7 @@ export class AddressesClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/compute/src/v1/region_operations_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute/src/v1/region_operations_client.ts.baseline
index ad23e0f60b5c..5f3553ef1ddf 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute/src/v1/region_operations_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute/src/v1/region_operations_client.ts.baseline
@@ -662,6 +662,7 @@ export class RegionOperationsClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_addresses_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_addresses_v1.ts.baseline
index b9a7c5e2bc90..a36f306abcb8 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_addresses_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_addresses_v1.ts.baseline
@@ -271,6 +271,7 @@ describe('v1.AddressesClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -287,6 +288,7 @@ describe('v1.AddressesClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_region_operations_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_region_operations_v1.ts.baseline
index b8e9446174b4..ce61791282f3 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_region_operations_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_region_operations_v1.ts.baseline
@@ -210,6 +210,7 @@ describe('v1.RegionOperationsClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -226,6 +227,7 @@ describe('v1.RegionOperationsClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/deprecatedtest-esm/esm/src/v1/deprecated_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/deprecatedtest-esm/esm/src/v1/deprecated_service_client.ts.baseline
index 7b4bbacd5373..e507092db5af 100644
--- a/core/generator/gapic-generator-typescript/baselines/deprecatedtest-esm/esm/src/v1/deprecated_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/deprecatedtest-esm/esm/src/v1/deprecated_service_client.ts.baseline
@@ -648,6 +648,7 @@ export class DeprecatedServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/deprecatedtest/src/v1/deprecated_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/deprecatedtest/src/v1/deprecated_service_client.ts.baseline
index 77a509591f4b..c29c49c68a08 100644
--- a/core/generator/gapic-generator-typescript/baselines/deprecatedtest/src/v1/deprecated_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/deprecatedtest/src/v1/deprecated_service_client.ts.baseline
@@ -626,6 +626,7 @@ export class DeprecatedServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/compliance_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/compliance_client.ts.baseline
index 69f08a41ea5b..81ee41ffcd63 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/compliance_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/compliance_client.ts.baseline
@@ -2203,6 +2203,7 @@ export class ComplianceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/echo_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/echo_client.ts.baseline
index 70b469d1124f..48fb44e9dd5a 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/echo_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/echo_client.ts.baseline
@@ -599,7 +599,7 @@ export class EchoClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.header;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -2068,6 +2068,7 @@ export class EchoClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/identity_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/identity_client.ts.baseline
index b268dbfd880a..30d01b9c5bf9 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/identity_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/identity_client.ts.baseline
@@ -1556,6 +1556,7 @@ export class IdentityClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/messaging_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/messaging_client.ts.baseline
index 591f45e5c37c..7e75cf009c20 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/messaging_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/messaging_client.ts.baseline
@@ -2670,6 +2670,7 @@ export class MessagingClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/sequence_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/sequence_service_client.ts.baseline
index 21f8cda3d856..bfc5ea769a31 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/sequence_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/sequence_service_client.ts.baseline
@@ -1229,6 +1229,7 @@ export class SequenceServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/testing_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/testing_client.ts.baseline
index 3aa0b740c8fb..bb7abfb366d4 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/testing_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/src/v1beta1/testing_client.ts.baseline
@@ -2043,6 +2043,7 @@ export class TestingClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_compliance_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
index ceaf5fbd537c..20a3891b7d93 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
@@ -161,6 +161,7 @@ describe('v1beta1.ComplianceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -177,6 +178,7 @@ describe('v1beta1.ComplianceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_echo_v1beta1.ts.baseline
index 99b1df3c0456..0d5540b77059 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_echo_v1beta1.ts.baseline
@@ -304,6 +304,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -320,6 +321,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_identity_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_identity_v1beta1.ts.baseline
index 1ad01742cec6..1cb9cb307920 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_identity_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_identity_v1beta1.ts.baseline
@@ -222,6 +222,7 @@ describe('v1beta1.IdentityClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -238,6 +239,7 @@ describe('v1beta1.IdentityClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_messaging_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
index cadfe8b5fe9f..ffd4fdf763e8 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
@@ -304,6 +304,7 @@ describe('v1beta1.MessagingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -320,6 +321,7 @@ describe('v1beta1.MessagingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
index 6eebdeb6428d..b9e4f3e9097c 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
@@ -161,6 +161,7 @@ describe('v1beta1.SequenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -177,6 +178,7 @@ describe('v1beta1.SequenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_testing_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_testing_v1beta1.ts.baseline
index 6d33fa6f5aca..14b0f953fd35 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_testing_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_testing_v1beta1.ts.baseline
@@ -222,6 +222,7 @@ describe('v1beta1.TestingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -238,6 +239,7 @@ describe('v1beta1.TestingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/compliance_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/compliance_client.ts.baseline
index b768905aa55b..a07a89a9ba8f 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/compliance_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/compliance_client.ts.baseline
@@ -2181,6 +2181,7 @@ export class ComplianceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/echo_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/echo_client.ts.baseline
index ec075987670c..eb33b38d8877 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/echo_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/echo_client.ts.baseline
@@ -579,7 +579,7 @@ export class EchoClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.header;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -2048,6 +2048,7 @@ export class EchoClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/identity_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/identity_client.ts.baseline
index 3d3b893eadb0..063f0f702323 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/identity_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/identity_client.ts.baseline
@@ -1536,6 +1536,7 @@ export class IdentityClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/messaging_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/messaging_client.ts.baseline
index fd63e1b8af7c..3b42177b4a4e 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/messaging_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/messaging_client.ts.baseline
@@ -2650,6 +2650,7 @@ export class MessagingClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/sequence_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/sequence_service_client.ts.baseline
index 44b30fae4f28..244d732fea45 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/sequence_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/sequence_service_client.ts.baseline
@@ -1207,6 +1207,7 @@ export class SequenceServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/testing_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/testing_client.ts.baseline
index d5075f3f3436..805931ea0017 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/testing_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/src/v1beta1/testing_client.ts.baseline
@@ -2023,6 +2023,7 @@ export class TestingClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_compliance_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_compliance_v1beta1.ts.baseline
index 23e948c86278..2ee428d6bdb7 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_compliance_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_compliance_v1beta1.ts.baseline
@@ -150,6 +150,7 @@ describe('v1beta1.ComplianceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -166,6 +167,7 @@ describe('v1beta1.ComplianceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_echo_v1beta1.ts.baseline
index f100c32b0f48..57178731bc27 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_echo_v1beta1.ts.baseline
@@ -293,6 +293,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -309,6 +310,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_identity_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_identity_v1beta1.ts.baseline
index dc077a3318d1..f32f7f9210b5 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_identity_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_identity_v1beta1.ts.baseline
@@ -211,6 +211,7 @@ describe('v1beta1.IdentityClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -227,6 +228,7 @@ describe('v1beta1.IdentityClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_messaging_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_messaging_v1beta1.ts.baseline
index f4620f5805e6..6bf50c4a7ece 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_messaging_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_messaging_v1beta1.ts.baseline
@@ -293,6 +293,7 @@ describe('v1beta1.MessagingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -309,6 +310,7 @@ describe('v1beta1.MessagingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_sequence_service_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_sequence_service_v1beta1.ts.baseline
index 47957341929a..8fed411f2e64 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_sequence_service_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_sequence_service_v1beta1.ts.baseline
@@ -150,6 +150,7 @@ describe('v1beta1.SequenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -166,6 +167,7 @@ describe('v1beta1.SequenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_testing_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_testing_v1beta1.ts.baseline
index 2bf22dce4398..75f225c4b150 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_testing_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_testing_v1beta1.ts.baseline
@@ -211,6 +211,7 @@ describe('v1beta1.TestingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -227,6 +228,7 @@ describe('v1beta1.TestingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/src/v2/dlp_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/src/v2/dlp_service_client.ts.baseline
index 2e5da567b338..ef08facdb816 100644
--- a/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/src/v2/dlp_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/src/v2/dlp_service_client.ts.baseline
@@ -6127,6 +6127,7 @@ export class DlpServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/test/gapic_dlp_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/test/gapic_dlp_service_v2.ts.baseline
index 20ea4f948448..74ec0ac2ff1f 100644
--- a/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/test/gapic_dlp_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/test/gapic_dlp_service_v2.ts.baseline
@@ -269,6 +269,7 @@ describe('v2.DlpServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -285,6 +286,7 @@ describe('v2.DlpServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/dlp/src/v2/dlp_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/dlp/src/v2/dlp_service_client.ts.baseline
index d41869473009..88b1f010f318 100644
--- a/core/generator/gapic-generator-typescript/baselines/dlp/src/v2/dlp_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/dlp/src/v2/dlp_service_client.ts.baseline
@@ -6105,6 +6105,7 @@ export class DlpServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/dlp/test/gapic_dlp_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/dlp/test/gapic_dlp_service_v2.ts.baseline
index 74ecdace0470..af75ba099eb2 100644
--- a/core/generator/gapic-generator-typescript/baselines/dlp/test/gapic_dlp_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/dlp/test/gapic_dlp_service_v2.ts.baseline
@@ -258,6 +258,7 @@ describe('v2.DlpServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -274,6 +275,7 @@ describe('v2.DlpServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/src/v1/duplicate_methods_test_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/src/v1/duplicate_methods_test_service_client.ts.baseline
index aaa23a82aef7..5e41d48a6e16 100644
--- a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/src/v1/duplicate_methods_test_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/src/v1/duplicate_methods_test_service_client.ts.baseline
@@ -1058,6 +1058,7 @@ export class DuplicateMethodsTestServiceClient {
         this.locationsClient.close().catch(err => {
           throw err;
         });
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline
index ba39da113702..b7a3b16f9def 100644
--- a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline
@@ -293,6 +293,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -312,6 +313,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -1217,20 +1219,24 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
         .stub()
         .callsArgWith(2, null, expectedResponse);
       const promise = new Promise((resolve, reject) => {
-        client.getLocation(
-          request,
-          expectedOptions,
-          (
-            err?: Error | null,
-            result?: LocationProtos.google.cloud.location.ILocation | null,
-          ) => {
-            if (err) {
-              reject(err);
-            } else {
-              resolve(result);
-            }
-          },
-        );
+        client
+          .getLocation(
+            request,
+            expectedOptions,
+            (
+              err?: Error | null,
+              result?: LocationProtos.google.cloud.location.ILocation | null,
+            ) => {
+              if (err) {
+                reject(err);
+              } else {
+                resolve(result);
+              }
+            },
+          )
+          .catch(err => {
+            throw err;
+          });
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
diff --git a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/src/v1/duplicate_methods_test_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/src/v1/duplicate_methods_test_service_client.ts.baseline
index 7a2a781bcfbf..44c745d6a7a0 100644
--- a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/src/v1/duplicate_methods_test_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/src/v1/duplicate_methods_test_service_client.ts.baseline
@@ -1036,6 +1036,7 @@ export class DuplicateMethodsTestServiceClient {
         this.locationsClient.close().catch(err => {
           throw err;
         });
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline
index a15b705a2554..bf984ae24aaf 100644
--- a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline
@@ -282,6 +282,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -301,6 +302,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -1206,20 +1208,24 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
         .stub()
         .callsArgWith(2, null, expectedResponse);
       const promise = new Promise((resolve, reject) => {
-        client.getLocation(
-          request,
-          expectedOptions,
-          (
-            err?: Error | null,
-            result?: LocationProtos.google.cloud.location.ILocation | null,
-          ) => {
-            if (err) {
-              reject(err);
-            } else {
-              resolve(result);
-            }
-          },
-        );
+        client
+          .getLocation(
+            request,
+            expectedOptions,
+            (
+              err?: Error | null,
+              result?: LocationProtos.google.cloud.location.ILocation | null,
+            ) => {
+              if (err) {
+                reject(err);
+              } else {
+                resolve(result);
+              }
+            },
+          )
+          .catch(err => {
+            throw err;
+          });
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
diff --git a/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/src/v1/key_management_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/src/v1/key_management_service_client.ts.baseline
index 073bd98a492b..2a58f15c3781 100644
--- a/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/src/v1/key_management_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/src/v1/key_management_service_client.ts.baseline
@@ -4174,6 +4174,7 @@ export class KeyManagementServiceClient {
         this.iamClient.close().catch(err => {
           throw err;
         });
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline
index c79cef85bcf7..d89d4d9da2bd 100644
--- a/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline
@@ -282,6 +282,7 @@ describe('v1.KeyManagementServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -299,6 +300,7 @@ describe('v1.KeyManagementServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/kms/src/v1/key_management_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/kms/src/v1/key_management_service_client.ts.baseline
index 145115231276..663a1e0e5275 100644
--- a/core/generator/gapic-generator-typescript/baselines/kms/src/v1/key_management_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/kms/src/v1/key_management_service_client.ts.baseline
@@ -4152,6 +4152,7 @@ export class KeyManagementServiceClient {
         this.iamClient.close().catch(err => {
           throw err;
         });
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline
index 1230c1308652..488bc6058592 100644
--- a/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline
@@ -271,6 +271,7 @@ describe('v1.KeyManagementServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -288,6 +289,7 @@ describe('v1.KeyManagementServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/config_service_v2_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/config_service_v2_client.ts.baseline
index 42200bd41961..7618045902b8 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/config_service_v2_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/config_service_v2_client.ts.baseline
@@ -6099,6 +6099,7 @@ export class ConfigServiceV2Client {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/logging_service_v2_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/logging_service_v2_client.ts.baseline
index dc924e83deea..24155a1266a9 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/logging_service_v2_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/logging_service_v2_client.ts.baseline
@@ -3063,6 +3063,7 @@ export class LoggingServiceV2Client {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/metrics_service_v2_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/metrics_service_v2_client.ts.baseline
index 2fca799a449d..a465c54a9853 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/metrics_service_v2_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/src/v2/metrics_service_v2_client.ts.baseline
@@ -2589,6 +2589,7 @@ export class MetricsServiceV2Client {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_config_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_config_service_v2_v2.ts.baseline
index fcbed530076c..c11f2c70cc20 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_config_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_config_service_v2_v2.ts.baseline
@@ -303,6 +303,7 @@ describe('v2.ConfigServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -319,6 +320,7 @@ describe('v2.ConfigServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_logging_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_logging_service_v2_v2.ts.baseline
index 6a3891d8f3f9..91fdb2c51e0f 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_logging_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_logging_service_v2_v2.ts.baseline
@@ -285,6 +285,7 @@ describe('v2.LoggingServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -301,6 +302,7 @@ describe('v2.LoggingServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_metrics_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_metrics_service_v2_v2.ts.baseline
index 091e515e1951..e0ee3b493df1 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_metrics_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_metrics_service_v2_v2.ts.baseline
@@ -271,6 +271,7 @@ describe('v2.MetricsServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -287,6 +288,7 @@ describe('v2.MetricsServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/logging/src/v2/config_service_v2_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging/src/v2/config_service_v2_client.ts.baseline
index 6ae1f4cb5bf9..36316d8daaa6 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging/src/v2/config_service_v2_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging/src/v2/config_service_v2_client.ts.baseline
@@ -6077,6 +6077,7 @@ export class ConfigServiceV2Client {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/logging/src/v2/logging_service_v2_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging/src/v2/logging_service_v2_client.ts.baseline
index 6eeb7e0e2982..1ad1582c68fe 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging/src/v2/logging_service_v2_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging/src/v2/logging_service_v2_client.ts.baseline
@@ -3041,6 +3041,7 @@ export class LoggingServiceV2Client {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/logging/src/v2/metrics_service_v2_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging/src/v2/metrics_service_v2_client.ts.baseline
index bb3751effdfe..ce60cc16a0fb 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging/src/v2/metrics_service_v2_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging/src/v2/metrics_service_v2_client.ts.baseline
@@ -2567,6 +2567,7 @@ export class MetricsServiceV2Client {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_config_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_config_service_v2_v2.ts.baseline
index 311ca8214c35..0b0614495fac 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_config_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_config_service_v2_v2.ts.baseline
@@ -292,6 +292,7 @@ describe('v2.ConfigServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -308,6 +309,7 @@ describe('v2.ConfigServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_logging_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_logging_service_v2_v2.ts.baseline
index a6b36839a535..22524ce75e5e 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_logging_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_logging_service_v2_v2.ts.baseline
@@ -274,6 +274,7 @@ describe('v2.LoggingServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -290,6 +291,7 @@ describe('v2.LoggingServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_metrics_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_metrics_service_v2_v2.ts.baseline
index 7af0dacc7ea5..867b1dffc732 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_metrics_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_metrics_service_v2_v2.ts.baseline
@@ -260,6 +260,7 @@ describe('v2.MetricsServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -276,6 +277,7 @@ describe('v2.MetricsServiceV2Client', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/alert_policy_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/alert_policy_service_client.ts.baseline
index 2a862b0cb4d2..3cd87333a25a 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/alert_policy_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/alert_policy_service_client.ts.baseline
@@ -2512,6 +2512,7 @@ export class AlertPolicyServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/group_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/group_service_client.ts.baseline
index 432754fab30c..b38a51ee8a87 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/group_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/group_service_client.ts.baseline
@@ -2723,6 +2723,7 @@ export class GroupServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/metric_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/metric_service_client.ts.baseline
index 857d4a0f217a..8c6f9981febb 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/metric_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/metric_service_client.ts.baseline
@@ -3518,6 +3518,7 @@ export class MetricServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/notification_channel_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/notification_channel_service_client.ts.baseline
index b5331dc17fd2..030b92c6de5b 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/notification_channel_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/notification_channel_service_client.ts.baseline
@@ -3448,6 +3448,7 @@ export class NotificationChannelServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/service_monitoring_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/service_monitoring_service_client.ts.baseline
index 426493910c69..c28ef190e01a 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/service_monitoring_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/service_monitoring_service_client.ts.baseline
@@ -3300,6 +3300,7 @@ export class ServiceMonitoringServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/uptime_check_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/uptime_check_service_client.ts.baseline
index bcd703dca0b4..56014d9a4e4c 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/uptime_check_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/src/v3/uptime_check_service_client.ts.baseline
@@ -2713,6 +2713,7 @@ export class UptimeCheckServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_alert_policy_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_alert_policy_service_v3.ts.baseline
index f38d230a7179..50c96488cd6d 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_alert_policy_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_alert_policy_service_v3.ts.baseline
@@ -273,6 +273,7 @@ describe('v3.AlertPolicyServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -289,6 +290,7 @@ describe('v3.AlertPolicyServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_group_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_group_service_v3.ts.baseline
index 467e49ec2ffb..1620bfa2b86f 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_group_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_group_service_v3.ts.baseline
@@ -271,6 +271,7 @@ describe('v3.GroupServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -287,6 +288,7 @@ describe('v3.GroupServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_metric_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_metric_service_v3.ts.baseline
index 74fb4d423418..d68422e7264e 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_metric_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_metric_service_v3.ts.baseline
@@ -271,6 +271,7 @@ describe('v3.MetricServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -287,6 +288,7 @@ describe('v3.MetricServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_notification_channel_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_notification_channel_service_v3.ts.baseline
index 81f1c6353718..3ee187438f3b 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_notification_channel_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_notification_channel_service_v3.ts.baseline
@@ -290,6 +290,7 @@ describe('v3.NotificationChannelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -309,6 +310,7 @@ describe('v3.NotificationChannelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_service_monitoring_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_service_monitoring_service_v3.ts.baseline
index ce19ca449a98..f2afe6d80703 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_service_monitoring_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_service_monitoring_service_v3.ts.baseline
@@ -284,6 +284,7 @@ describe('v3.ServiceMonitoringServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -301,6 +302,7 @@ describe('v3.ServiceMonitoringServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_uptime_check_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_uptime_check_service_v3.ts.baseline
index bd3346886427..b351af6e64a4 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_uptime_check_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_uptime_check_service_v3.ts.baseline
@@ -273,6 +273,7 @@ describe('v3.UptimeCheckServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -289,6 +290,7 @@ describe('v3.UptimeCheckServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/alert_policy_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/alert_policy_service_client.ts.baseline
index befbb4991224..e493ec6cd58f 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/alert_policy_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/alert_policy_service_client.ts.baseline
@@ -2490,6 +2490,7 @@ export class AlertPolicyServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/group_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/group_service_client.ts.baseline
index ae83c79765d8..96127cb2edad 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/group_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/group_service_client.ts.baseline
@@ -2701,6 +2701,7 @@ export class GroupServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/metric_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/metric_service_client.ts.baseline
index 255d0e0ff754..350d9738b6b1 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/metric_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/metric_service_client.ts.baseline
@@ -3496,6 +3496,7 @@ export class MetricServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/notification_channel_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/notification_channel_service_client.ts.baseline
index 1d026fd19fc0..c2d6653581b6 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/notification_channel_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/notification_channel_service_client.ts.baseline
@@ -3426,6 +3426,7 @@ export class NotificationChannelServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/service_monitoring_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/service_monitoring_service_client.ts.baseline
index f654cf28a646..456c2c94509f 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/service_monitoring_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/service_monitoring_service_client.ts.baseline
@@ -3278,6 +3278,7 @@ export class ServiceMonitoringServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/uptime_check_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/uptime_check_service_client.ts.baseline
index 3130307fce97..e9f596355d30 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/uptime_check_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/src/v3/uptime_check_service_client.ts.baseline
@@ -2691,6 +2691,7 @@ export class UptimeCheckServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_alert_policy_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_alert_policy_service_v3.ts.baseline
index 030c4eba3051..24bf1707e142 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_alert_policy_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_alert_policy_service_v3.ts.baseline
@@ -262,6 +262,7 @@ describe('v3.AlertPolicyServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -278,6 +279,7 @@ describe('v3.AlertPolicyServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_group_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_group_service_v3.ts.baseline
index fb8ed7b81f1d..e6f11585139e 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_group_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_group_service_v3.ts.baseline
@@ -260,6 +260,7 @@ describe('v3.GroupServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -276,6 +277,7 @@ describe('v3.GroupServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_metric_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_metric_service_v3.ts.baseline
index 1cd15163e37d..e62d5170f4dc 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_metric_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_metric_service_v3.ts.baseline
@@ -260,6 +260,7 @@ describe('v3.MetricServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -276,6 +277,7 @@ describe('v3.MetricServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_notification_channel_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_notification_channel_service_v3.ts.baseline
index 68b508a413be..d8be2e56c529 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_notification_channel_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_notification_channel_service_v3.ts.baseline
@@ -279,6 +279,7 @@ describe('v3.NotificationChannelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -298,6 +299,7 @@ describe('v3.NotificationChannelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_service_monitoring_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_service_monitoring_service_v3.ts.baseline
index 2cf3edee2c36..64e9f88ceaf5 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_service_monitoring_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_service_monitoring_service_v3.ts.baseline
@@ -273,6 +273,7 @@ describe('v3.ServiceMonitoringServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -290,6 +291,7 @@ describe('v3.ServiceMonitoringServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_uptime_check_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_uptime_check_service_v3.ts.baseline
index 95faeab5e275..305637d15e43 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_uptime_check_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_uptime_check_service_v3.ts.baseline
@@ -262,6 +262,7 @@ describe('v3.UptimeCheckServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -278,6 +279,7 @@ describe('v3.UptimeCheckServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/src/v1beta1/naming_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/src/v1beta1/naming_client.ts.baseline
index 3c0d5a4a88eb..eb18305e1ce9 100644
--- a/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/src/v1beta1/naming_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/src/v1beta1/naming_client.ts.baseline
@@ -2179,6 +2179,7 @@ export class NamingClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/test/gapic_naming_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/test/gapic_naming_v1beta1.ts.baseline
index fdc23a23e660..ee79ada183c0 100644
--- a/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/test/gapic_naming_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/test/gapic_naming_v1beta1.ts.baseline
@@ -254,6 +254,7 @@ describe('v1beta1.NamingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -270,6 +271,7 @@ describe('v1beta1.NamingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/naming/src/v1beta1/naming_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/naming/src/v1beta1/naming_client.ts.baseline
index dba352c6df4b..a92a75212f0d 100644
--- a/core/generator/gapic-generator-typescript/baselines/naming/src/v1beta1/naming_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/naming/src/v1beta1/naming_client.ts.baseline
@@ -2159,6 +2159,7 @@ export class NamingClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/naming/test/gapic_naming_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/naming/test/gapic_naming_v1beta1.ts.baseline
index 31a9b00930e2..3a396e5da3a3 100644
--- a/core/generator/gapic-generator-typescript/baselines/naming/test/gapic_naming_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/naming/test/gapic_naming_v1beta1.ts.baseline
@@ -243,6 +243,7 @@ describe('v1beta1.NamingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -259,6 +260,7 @@ describe('v1beta1.NamingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/src/v1beta1/cloud_redis_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/src/v1beta1/cloud_redis_client.ts.baseline
index 4801f4a4a21b..76f57b528d6f 100644
--- a/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/src/v1beta1/cloud_redis_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/src/v1beta1/cloud_redis_client.ts.baseline
@@ -2290,6 +2290,7 @@ export class CloudRedisClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline
index 93b72bae3c5c..988ba98126c7 100644
--- a/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline
@@ -303,6 +303,7 @@ describe('v1beta1.CloudRedisClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -319,6 +320,7 @@ describe('v1beta1.CloudRedisClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/redis/src/v1beta1/cloud_redis_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/redis/src/v1beta1/cloud_redis_client.ts.baseline
index dee2544ebaeb..6db8b079ab61 100644
--- a/core/generator/gapic-generator-typescript/baselines/redis/src/v1beta1/cloud_redis_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/redis/src/v1beta1/cloud_redis_client.ts.baseline
@@ -2268,6 +2268,7 @@ export class CloudRedisClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline
index eb82487dcfbe..771c75747f7b 100644
--- a/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline
@@ -292,6 +292,7 @@ describe('v1beta1.CloudRedisClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -308,6 +309,7 @@ describe('v1beta1.CloudRedisClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/analytics_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/analytics_service_client.ts.baseline
index c5cd622e739d..0a0ebea0d0b6 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/analytics_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/analytics_service_client.ts.baseline
@@ -1354,6 +1354,7 @@ export class AnalyticsServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/branch_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/branch_service_client.ts.baseline
index a740c0ea1ac2..465b06481505 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/branch_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/branch_service_client.ts.baseline
@@ -1385,6 +1385,7 @@ export class BranchServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/catalog_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/catalog_service_client.ts.baseline
index 5e009f57fd43..53cd47952e83 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/catalog_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/catalog_service_client.ts.baseline
@@ -3145,6 +3145,7 @@ export class CatalogServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/completion_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/completion_service_client.ts.baseline
index 4b33b94b4c74..235556a53088 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/completion_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/completion_service_client.ts.baseline
@@ -1566,6 +1566,7 @@ export class CompletionServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/control_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/control_service_client.ts.baseline
index b2e78eba4770..fb565baffc10 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/control_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/control_service_client.ts.baseline
@@ -1929,6 +1929,7 @@ export class ControlServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/conversational_search_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/conversational_search_service_client.ts.baseline
index 43c49533a33c..a13d4b95dfb9 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/conversational_search_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/conversational_search_service_client.ts.baseline
@@ -1218,6 +1218,7 @@ export class ConversationalSearchServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/generative_question_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/generative_question_service_client.ts.baseline
index 41d0789ac275..c80ff66b3dcf 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/generative_question_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/generative_question_service_client.ts.baseline
@@ -1870,6 +1870,7 @@ export class GenerativeQuestionServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/merchant_center_account_link_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/merchant_center_account_link_service_client.ts.baseline
index a6548a6bdaa7..ed6355534808 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/merchant_center_account_link_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/merchant_center_account_link_service_client.ts.baseline
@@ -1661,6 +1661,7 @@ export class MerchantCenterAccountLinkServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/model_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/model_service_client.ts.baseline
index c1bd7189e541..a774da6878a9 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/model_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/model_service_client.ts.baseline
@@ -2431,6 +2431,7 @@ export class ModelServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/prediction_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/prediction_service_client.ts.baseline
index 38ca3c0f0e8b..f938bacf19a7 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/prediction_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/prediction_service_client.ts.baseline
@@ -1349,6 +1349,7 @@ export class PredictionServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/product_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/product_service_client.ts.baseline
index 2f1662f2bd41..8084893926b0 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/product_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/product_service_client.ts.baseline
@@ -4244,6 +4244,7 @@ export class ProductServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/project_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/project_service_client.ts.baseline
index 843ad929644c..469a73d915bb 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/project_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/project_service_client.ts.baseline
@@ -2363,6 +2363,7 @@ export class ProjectServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/search_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/search_service_client.ts.baseline
index 8a6c5ed052cb..5dcf32b1bc0f 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/search_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/search_service_client.ts.baseline
@@ -2284,6 +2284,7 @@ export class SearchServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/serving_config_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/serving_config_service_client.ts.baseline
index 545b5fbcdcb0..878ddbb28eb5 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/serving_config_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/serving_config_service_client.ts.baseline
@@ -2226,6 +2226,7 @@ export class ServingConfigServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/user_event_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/user_event_service_client.ts.baseline
index 2454aa07c327..4f920b358eea 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/user_event_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/src/v2alpha/user_event_service_client.ts.baseline
@@ -2280,6 +2280,7 @@ export class UserEventServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_analytics_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_analytics_service_v2alpha.ts.baseline
index 08fec77ede3d..a2fd45338e38 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_analytics_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_analytics_service_v2alpha.ts.baseline
@@ -236,6 +236,7 @@ describe('v2alpha.AnalyticsServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -252,6 +253,7 @@ describe('v2alpha.AnalyticsServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_branch_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_branch_service_v2alpha.ts.baseline
index 95a6a707acfd..1910a3e55980 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_branch_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_branch_service_v2alpha.ts.baseline
@@ -208,6 +208,7 @@ describe('v2alpha.BranchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -224,6 +225,7 @@ describe('v2alpha.BranchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_catalog_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_catalog_service_v2alpha.ts.baseline
index 01e6058a4d49..83628567c754 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_catalog_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_catalog_service_v2alpha.ts.baseline
@@ -272,6 +272,7 @@ describe('v2alpha.CatalogServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -288,6 +289,7 @@ describe('v2alpha.CatalogServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_completion_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_completion_service_v2alpha.ts.baseline
index 5d670e4e9d44..31af7c27094e 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_completion_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_completion_service_v2alpha.ts.baseline
@@ -250,6 +250,7 @@ describe('v2alpha.CompletionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -267,6 +268,7 @@ describe('v2alpha.CompletionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_control_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_control_service_v2alpha.ts.baseline
index e48de954b9ba..1268a3016685 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_control_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_control_service_v2alpha.ts.baseline
@@ -272,6 +272,7 @@ describe('v2alpha.ControlServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -288,6 +289,7 @@ describe('v2alpha.ControlServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_conversational_search_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_conversational_search_service_v2alpha.ts.baseline
index e678fbb3cf65..c071c8b2c8ea 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_conversational_search_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_conversational_search_service_v2alpha.ts.baseline
@@ -235,6 +235,7 @@ describe('v2alpha.ConversationalSearchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -254,6 +255,7 @@ describe('v2alpha.ConversationalSearchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_generative_question_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_generative_question_service_v2alpha.ts.baseline
index 26a7d6e50e04..61722e63127b 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_generative_question_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_generative_question_service_v2alpha.ts.baseline
@@ -227,6 +227,7 @@ describe('v2alpha.GenerativeQuestionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -246,6 +247,7 @@ describe('v2alpha.GenerativeQuestionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
index 90cd9a5ed399..fbe5de8fe6e0 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
@@ -262,6 +262,7 @@ describe('v2alpha.MerchantCenterAccountLinkServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -284,6 +285,7 @@ describe('v2alpha.MerchantCenterAccountLinkServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_model_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_model_service_v2alpha.ts.baseline
index a15dcb81dd56..1c5f191d298b 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_model_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_model_service_v2alpha.ts.baseline
@@ -303,6 +303,7 @@ describe('v2alpha.ModelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -319,6 +320,7 @@ describe('v2alpha.ModelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_prediction_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_prediction_service_v2alpha.ts.baseline
index 58b7843b0bc6..01b2a79e26f0 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_prediction_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_prediction_service_v2alpha.ts.baseline
@@ -218,6 +218,7 @@ describe('v2alpha.PredictionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -235,6 +236,7 @@ describe('v2alpha.PredictionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_product_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_product_service_v2alpha.ts.baseline
index 68c2620b23ad..c2ab22595e38 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_product_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_product_service_v2alpha.ts.baseline
@@ -304,6 +304,7 @@ describe('v2alpha.ProductServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -320,6 +321,7 @@ describe('v2alpha.ProductServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_project_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_project_service_v2alpha.ts.baseline
index 256b0e3ee9fb..ffa539fe5e9c 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_project_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_project_service_v2alpha.ts.baseline
@@ -241,6 +241,7 @@ describe('v2alpha.ProjectServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -257,6 +258,7 @@ describe('v2alpha.ProjectServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_search_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_search_service_v2alpha.ts.baseline
index ae99e8f11511..9cd1a26ba602 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_search_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_search_service_v2alpha.ts.baseline
@@ -271,6 +271,7 @@ describe('v2alpha.SearchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -287,6 +288,7 @@ describe('v2alpha.SearchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_serving_config_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_serving_config_service_v2alpha.ts.baseline
index 20460a53e451..9927d5ab72ed 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_serving_config_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_serving_config_service_v2alpha.ts.baseline
@@ -284,6 +284,7 @@ describe('v2alpha.ServingConfigServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -301,6 +302,7 @@ describe('v2alpha.ServingConfigServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_user_event_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_user_event_service_v2alpha.ts.baseline
index 5cff6855b958..b50bea4bf0ef 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_user_event_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_user_event_service_v2alpha.ts.baseline
@@ -245,6 +245,7 @@ describe('v2alpha.UserEventServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -261,6 +262,7 @@ describe('v2alpha.UserEventServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/analytics_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/analytics_service_client.ts.baseline
index 5ea8293ee40e..dd1d67d5d756 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/analytics_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/analytics_service_client.ts.baseline
@@ -1332,6 +1332,7 @@ export class AnalyticsServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/branch_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/branch_service_client.ts.baseline
index b49b43ed183f..5e5cc979089d 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/branch_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/branch_service_client.ts.baseline
@@ -1363,6 +1363,7 @@ export class BranchServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/catalog_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/catalog_service_client.ts.baseline
index 2da8338557b3..d3e453fab653 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/catalog_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/catalog_service_client.ts.baseline
@@ -3123,6 +3123,7 @@ export class CatalogServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/completion_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/completion_service_client.ts.baseline
index 726e847f90f5..5b2597e40846 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/completion_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/completion_service_client.ts.baseline
@@ -1544,6 +1544,7 @@ export class CompletionServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/control_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/control_service_client.ts.baseline
index 1a18b3cf0bb3..74d777c18ee2 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/control_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/control_service_client.ts.baseline
@@ -1907,6 +1907,7 @@ export class ControlServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/conversational_search_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/conversational_search_service_client.ts.baseline
index 4f196bc99b5c..7a54bfde63a6 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/conversational_search_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/conversational_search_service_client.ts.baseline
@@ -1196,6 +1196,7 @@ export class ConversationalSearchServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/generative_question_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/generative_question_service_client.ts.baseline
index a69bb00a0b16..6a252366e3ad 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/generative_question_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/generative_question_service_client.ts.baseline
@@ -1848,6 +1848,7 @@ export class GenerativeQuestionServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/merchant_center_account_link_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/merchant_center_account_link_service_client.ts.baseline
index 253498044905..6513be7df5d9 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/merchant_center_account_link_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/merchant_center_account_link_service_client.ts.baseline
@@ -1639,6 +1639,7 @@ export class MerchantCenterAccountLinkServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/model_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/model_service_client.ts.baseline
index 8968244be5d6..0d872141d30a 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/model_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/model_service_client.ts.baseline
@@ -2409,6 +2409,7 @@ export class ModelServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/prediction_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/prediction_service_client.ts.baseline
index f0662a6a537c..cd322e54cd6e 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/prediction_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/prediction_service_client.ts.baseline
@@ -1327,6 +1327,7 @@ export class PredictionServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/product_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/product_service_client.ts.baseline
index 2996785da40d..4d09772e199c 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/product_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/product_service_client.ts.baseline
@@ -4222,6 +4222,7 @@ export class ProductServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/project_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/project_service_client.ts.baseline
index 98e9989a5e1a..6b7579303c97 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/project_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/project_service_client.ts.baseline
@@ -2341,6 +2341,7 @@ export class ProjectServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/search_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/search_service_client.ts.baseline
index 4cca14272af7..4c1af357b725 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/search_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/search_service_client.ts.baseline
@@ -2262,6 +2262,7 @@ export class SearchServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/serving_config_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/serving_config_service_client.ts.baseline
index f37c11c00f6b..7ae4d230e89c 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/serving_config_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/serving_config_service_client.ts.baseline
@@ -2204,6 +2204,7 @@ export class ServingConfigServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/user_event_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/user_event_service_client.ts.baseline
index 0f85e66c314b..5be8d5dac634 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/user_event_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/src/v2alpha/user_event_service_client.ts.baseline
@@ -2258,6 +2258,7 @@ export class UserEventServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_analytics_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_analytics_service_v2alpha.ts.baseline
index 01db00a73149..5cfe52e9002d 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_analytics_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_analytics_service_v2alpha.ts.baseline
@@ -225,6 +225,7 @@ describe('v2alpha.AnalyticsServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -241,6 +242,7 @@ describe('v2alpha.AnalyticsServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_branch_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_branch_service_v2alpha.ts.baseline
index 43cafcb1bd65..40a22dd4ac7a 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_branch_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_branch_service_v2alpha.ts.baseline
@@ -197,6 +197,7 @@ describe('v2alpha.BranchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -213,6 +214,7 @@ describe('v2alpha.BranchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_catalog_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_catalog_service_v2alpha.ts.baseline
index fc3c28c8171f..b418212c6b69 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_catalog_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_catalog_service_v2alpha.ts.baseline
@@ -261,6 +261,7 @@ describe('v2alpha.CatalogServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -277,6 +278,7 @@ describe('v2alpha.CatalogServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_completion_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_completion_service_v2alpha.ts.baseline
index 7ffaf2b53121..5bbf2721dcb1 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_completion_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_completion_service_v2alpha.ts.baseline
@@ -239,6 +239,7 @@ describe('v2alpha.CompletionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -256,6 +257,7 @@ describe('v2alpha.CompletionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_control_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_control_service_v2alpha.ts.baseline
index 75507622f8b9..fdb3bcee12bc 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_control_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_control_service_v2alpha.ts.baseline
@@ -261,6 +261,7 @@ describe('v2alpha.ControlServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -277,6 +278,7 @@ describe('v2alpha.ControlServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_conversational_search_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_conversational_search_service_v2alpha.ts.baseline
index 48d0e8f49553..7120acc5d119 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_conversational_search_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_conversational_search_service_v2alpha.ts.baseline
@@ -224,6 +224,7 @@ describe('v2alpha.ConversationalSearchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -243,6 +244,7 @@ describe('v2alpha.ConversationalSearchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_generative_question_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_generative_question_service_v2alpha.ts.baseline
index 36533bbed00b..77fb854cd818 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_generative_question_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_generative_question_service_v2alpha.ts.baseline
@@ -216,6 +216,7 @@ describe('v2alpha.GenerativeQuestionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -235,6 +236,7 @@ describe('v2alpha.GenerativeQuestionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
index a99332fffd68..d1bedf1f3550 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
@@ -251,6 +251,7 @@ describe('v2alpha.MerchantCenterAccountLinkServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -273,6 +274,7 @@ describe('v2alpha.MerchantCenterAccountLinkServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_model_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_model_service_v2alpha.ts.baseline
index c7d6259bc8b9..403dc23c596f 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_model_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_model_service_v2alpha.ts.baseline
@@ -292,6 +292,7 @@ describe('v2alpha.ModelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -308,6 +309,7 @@ describe('v2alpha.ModelServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_prediction_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_prediction_service_v2alpha.ts.baseline
index 7b98117d5ec9..6668326f938e 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_prediction_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_prediction_service_v2alpha.ts.baseline
@@ -207,6 +207,7 @@ describe('v2alpha.PredictionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -224,6 +225,7 @@ describe('v2alpha.PredictionServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_product_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_product_service_v2alpha.ts.baseline
index fe17b18d523a..1a2a1df9ebc4 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_product_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_product_service_v2alpha.ts.baseline
@@ -293,6 +293,7 @@ describe('v2alpha.ProductServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -309,6 +310,7 @@ describe('v2alpha.ProductServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_project_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_project_service_v2alpha.ts.baseline
index 7883d5f5f865..d10d243c2f6e 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_project_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_project_service_v2alpha.ts.baseline
@@ -230,6 +230,7 @@ describe('v2alpha.ProjectServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -246,6 +247,7 @@ describe('v2alpha.ProjectServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_search_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_search_service_v2alpha.ts.baseline
index cbf6aa9394dc..6a5c6bca776e 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_search_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_search_service_v2alpha.ts.baseline
@@ -260,6 +260,7 @@ describe('v2alpha.SearchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -276,6 +277,7 @@ describe('v2alpha.SearchServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_serving_config_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_serving_config_service_v2alpha.ts.baseline
index c6b795731687..516da0ffe48b 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_serving_config_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_serving_config_service_v2alpha.ts.baseline
@@ -273,6 +273,7 @@ describe('v2alpha.ServingConfigServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -290,6 +291,7 @@ describe('v2alpha.ServingConfigServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_user_event_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_user_event_service_v2alpha.ts.baseline
index 1e4c88216ecb..9cc85191b8c8 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_user_event_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_user_event_service_v2alpha.ts.baseline
@@ -234,6 +234,7 @@ describe('v2alpha.UserEventServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -250,6 +251,7 @@ describe('v2alpha.UserEventServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/src/v1/test_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/src/v1/test_service_client.ts.baseline
index 93b2724c3679..43dc89d23724 100644
--- a/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/src/v1/test_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/src/v1/test_service_client.ts.baseline
@@ -463,7 +463,7 @@ export class TestServiceClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.name;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -606,7 +606,7 @@ export class TestServiceClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.name;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -757,7 +757,7 @@ export class TestServiceClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.parentId;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -858,6 +858,7 @@ export class TestServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/test/gapic_test_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/test/gapic_test_service_v1.ts.baseline
index f51ca9bd7ef4..ab4202aad645 100644
--- a/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/test/gapic_test_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/test/gapic_test_service_v1.ts.baseline
@@ -159,6 +159,7 @@ describe('v1.TestServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -175,6 +176,7 @@ describe('v1.TestServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/routingtest/src/v1/test_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/routingtest/src/v1/test_service_client.ts.baseline
index 98b43fe6843a..306fbc01ba4e 100644
--- a/core/generator/gapic-generator-typescript/baselines/routingtest/src/v1/test_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/routingtest/src/v1/test_service_client.ts.baseline
@@ -441,7 +441,7 @@ export class TestServiceClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.name;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -584,7 +584,7 @@ export class TestServiceClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.name;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -735,7 +735,7 @@ export class TestServiceClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.parentId;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -836,6 +836,7 @@ export class TestServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/routingtest/test/gapic_test_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/routingtest/test/gapic_test_service_v1.ts.baseline
index d288b0445d70..2cfa2bc540f6 100644
--- a/core/generator/gapic-generator-typescript/baselines/routingtest/test/gapic_test_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/routingtest/test/gapic_test_service_v1.ts.baseline
@@ -148,6 +148,7 @@ describe('v1.TestServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -164,6 +165,7 @@ describe('v1.TestServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/compliance_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/compliance_client.ts.baseline
index 612d13e8e323..38872c09cb32 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/compliance_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/compliance_client.ts.baseline
@@ -2206,6 +2206,7 @@ export class ComplianceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/echo_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/echo_client.ts.baseline
index a9ca832e08f8..bcd203cf5567 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/echo_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/echo_client.ts.baseline
@@ -668,7 +668,7 @@ export class EchoClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.header;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -2137,6 +2137,7 @@ export class EchoClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/identity_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/identity_client.ts.baseline
index 433c7cda3fb7..076032d5c411 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/identity_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/identity_client.ts.baseline
@@ -1559,6 +1559,7 @@ export class IdentityClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/messaging_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/messaging_client.ts.baseline
index a9a9144517ac..6cf3ae78f08b 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/messaging_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/messaging_client.ts.baseline
@@ -2736,6 +2736,7 @@ export class MessagingClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/sequence_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/sequence_service_client.ts.baseline
index a67f11b04d5f..6b64e16d6e44 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/sequence_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/sequence_service_client.ts.baseline
@@ -1232,6 +1232,7 @@ export class SequenceServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/testing_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/testing_client.ts.baseline
index 5a4ccdd86d6a..928e5b568afc 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/testing_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/src/v1beta1/testing_client.ts.baseline
@@ -2046,6 +2046,7 @@ export class TestingClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_compliance_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
index ceaf5fbd537c..20a3891b7d93 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
@@ -161,6 +161,7 @@ describe('v1beta1.ComplianceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -177,6 +178,7 @@ describe('v1beta1.ComplianceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_echo_v1beta1.ts.baseline
index c6b8789e840b..6225a291baf1 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_echo_v1beta1.ts.baseline
@@ -304,6 +304,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -320,6 +321,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_identity_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_identity_v1beta1.ts.baseline
index 1ad01742cec6..1cb9cb307920 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_identity_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_identity_v1beta1.ts.baseline
@@ -222,6 +222,7 @@ describe('v1beta1.IdentityClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -238,6 +239,7 @@ describe('v1beta1.IdentityClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_messaging_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
index cadfe8b5fe9f..ffd4fdf763e8 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
@@ -304,6 +304,7 @@ describe('v1beta1.MessagingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -320,6 +321,7 @@ describe('v1beta1.MessagingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
index 6eebdeb6428d..b9e4f3e9097c 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
@@ -161,6 +161,7 @@ describe('v1beta1.SequenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -177,6 +178,7 @@ describe('v1beta1.SequenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_testing_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_testing_v1beta1.ts.baseline
index 6d33fa6f5aca..14b0f953fd35 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_testing_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_testing_v1beta1.ts.baseline
@@ -222,6 +222,7 @@ describe('v1beta1.TestingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -238,6 +239,7 @@ describe('v1beta1.TestingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/src/v1beta1/echo_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/src/v1beta1/echo_client.ts.baseline
index b6e26159ac3e..e74ff36070f4 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/src/v1beta1/echo_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/src/v1beta1/echo_client.ts.baseline
@@ -537,7 +537,7 @@ export class EchoClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.header;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -1539,6 +1539,7 @@ export class EchoClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/test/gapic_echo_v1beta1.ts.baseline
index a48a9e82dad8..08d980cda4b8 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/test/gapic_echo_v1beta1.ts.baseline
@@ -279,6 +279,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -295,6 +296,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-legacy/src/v1beta1/echo_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-legacy/src/v1beta1/echo_client.ts.baseline
index 2cc98fb3ea7e..79d1505263a6 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-legacy/src/v1beta1/echo_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-legacy/src/v1beta1/echo_client.ts.baseline
@@ -521,7 +521,7 @@ export class EchoClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.header;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -1523,6 +1523,7 @@ export class EchoClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-legacy/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-legacy/test/gapic_echo_v1beta1.ts.baseline
index b31a9371fe43..35d262ccb66c 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-legacy/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-legacy/test/gapic_echo_v1beta1.ts.baseline
@@ -278,6 +278,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -294,6 +295,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/compliance_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/compliance_client.ts.baseline
index 2f3b3631b924..cafa64b29084 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/compliance_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/compliance_client.ts.baseline
@@ -2184,6 +2184,7 @@ export class ComplianceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/echo_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/echo_client.ts.baseline
index 4a05a3e7fe10..274fb6b9d065 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/echo_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/echo_client.ts.baseline
@@ -648,7 +648,7 @@ export class EchoClient {
     options = options || {};
     options.otherArgs = options.otherArgs || {};
     options.otherArgs.headers = options.otherArgs.headers || {};
-    let routingParameter = {};
+    const routingParameter = {};
     {
       const fieldValue = request.header;
       if (fieldValue !== undefined && fieldValue !== null) {
@@ -2117,6 +2117,7 @@ export class EchoClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/identity_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/identity_client.ts.baseline
index 8410b4ad2a72..ed1b6bba00f1 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/identity_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/identity_client.ts.baseline
@@ -1539,6 +1539,7 @@ export class IdentityClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/messaging_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/messaging_client.ts.baseline
index 23ce28b3d824..328344108840 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/messaging_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/messaging_client.ts.baseline
@@ -2716,6 +2716,7 @@ export class MessagingClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/sequence_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/sequence_service_client.ts.baseline
index bccea367c8a8..2e5370264270 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/sequence_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/sequence_service_client.ts.baseline
@@ -1210,6 +1210,7 @@ export class SequenceServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/testing_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/testing_client.ts.baseline
index f1ecf6ec2f17..b576c00bab5c 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/testing_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/src/v1beta1/testing_client.ts.baseline
@@ -2026,6 +2026,7 @@ export class TestingClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_compliance_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_compliance_v1beta1.ts.baseline
index 23e948c86278..2ee428d6bdb7 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_compliance_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_compliance_v1beta1.ts.baseline
@@ -150,6 +150,7 @@ describe('v1beta1.ComplianceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -166,6 +167,7 @@ describe('v1beta1.ComplianceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_echo_v1beta1.ts.baseline
index d1881f8f50b5..cf181d5f25a9 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_echo_v1beta1.ts.baseline
@@ -293,6 +293,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -309,6 +310,7 @@ describe('v1beta1.EchoClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_identity_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_identity_v1beta1.ts.baseline
index dc077a3318d1..f32f7f9210b5 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_identity_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_identity_v1beta1.ts.baseline
@@ -211,6 +211,7 @@ describe('v1beta1.IdentityClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -227,6 +228,7 @@ describe('v1beta1.IdentityClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_messaging_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_messaging_v1beta1.ts.baseline
index f4620f5805e6..6bf50c4a7ece 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_messaging_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_messaging_v1beta1.ts.baseline
@@ -293,6 +293,7 @@ describe('v1beta1.MessagingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -309,6 +310,7 @@ describe('v1beta1.MessagingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_sequence_service_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_sequence_service_v1beta1.ts.baseline
index 47957341929a..8fed411f2e64 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_sequence_service_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_sequence_service_v1beta1.ts.baseline
@@ -150,6 +150,7 @@ describe('v1beta1.SequenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -166,6 +167,7 @@ describe('v1beta1.SequenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_testing_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_testing_v1beta1.ts.baseline
index 2bf22dce4398..75f225c4b150 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_testing_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_testing_v1beta1.ts.baseline
@@ -211,6 +211,7 @@ describe('v1beta1.TestingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -227,6 +228,7 @@ describe('v1beta1.TestingClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/src/v2/cloud_tasks_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/src/v2/cloud_tasks_client.ts.baseline
index f4206ccc2168..f2386f1a9221 100644
--- a/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/src/v2/cloud_tasks_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/src/v2/cloud_tasks_client.ts.baseline
@@ -3119,6 +3119,7 @@ export class CloudTasksClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/test/gapic_cloud_tasks_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/test/gapic_cloud_tasks_v2.ts.baseline
index 8f140720693c..a75a1198747b 100644
--- a/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/test/gapic_cloud_tasks_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/test/gapic_cloud_tasks_v2.ts.baseline
@@ -269,6 +269,7 @@ describe('v2.CloudTasksClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -285,6 +286,7 @@ describe('v2.CloudTasksClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/tasks/src/v2/cloud_tasks_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/tasks/src/v2/cloud_tasks_client.ts.baseline
index 1e0d2d74f97f..878b2adb0168 100644
--- a/core/generator/gapic-generator-typescript/baselines/tasks/src/v2/cloud_tasks_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/tasks/src/v2/cloud_tasks_client.ts.baseline
@@ -3097,6 +3097,7 @@ export class CloudTasksClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/tasks/test/gapic_cloud_tasks_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/tasks/test/gapic_cloud_tasks_v2.ts.baseline
index 2bb1d0eb146f..e9559144ed91 100644
--- a/core/generator/gapic-generator-typescript/baselines/tasks/test/gapic_cloud_tasks_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/tasks/test/gapic_cloud_tasks_v2.ts.baseline
@@ -258,6 +258,7 @@ describe('v2.CloudTasksClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -274,6 +275,7 @@ describe('v2.CloudTasksClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/src/v1/text_to_speech_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/src/v1/text_to_speech_client.ts.baseline
index 019f086bf28d..12d6b7e5e9a7 100644
--- a/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/src/v1/text_to_speech_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/src/v1/text_to_speech_client.ts.baseline
@@ -659,6 +659,7 @@ export class TextToSpeechClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/test/gapic_text_to_speech_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/test/gapic_text_to_speech_v1.ts.baseline
index 3c44796a081d..03d6183f7d11 100644
--- a/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/test/gapic_text_to_speech_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/test/gapic_text_to_speech_v1.ts.baseline
@@ -211,6 +211,7 @@ describe('v1.TextToSpeechClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -227,6 +228,7 @@ describe('v1.TextToSpeechClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/texttospeech/src/v1/text_to_speech_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/texttospeech/src/v1/text_to_speech_client.ts.baseline
index eaebaefe8a18..e198672e4d7f 100644
--- a/core/generator/gapic-generator-typescript/baselines/texttospeech/src/v1/text_to_speech_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/texttospeech/src/v1/text_to_speech_client.ts.baseline
@@ -637,6 +637,7 @@ export class TextToSpeechClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/texttospeech/test/gapic_text_to_speech_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/texttospeech/test/gapic_text_to_speech_v1.ts.baseline
index 3393815f4858..9664d29025c7 100644
--- a/core/generator/gapic-generator-typescript/baselines/texttospeech/test/gapic_text_to_speech_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/texttospeech/test/gapic_text_to_speech_v1.ts.baseline
@@ -200,6 +200,7 @@ describe('v1.TextToSpeechClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -216,6 +217,7 @@ describe('v1.TextToSpeechClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/src/v3beta1/translation_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/src/v3beta1/translation_service_client.ts.baseline
index 160607b203a1..af25dd8247d7 100644
--- a/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/src/v3beta1/translation_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/src/v3beta1/translation_service_client.ts.baseline
@@ -2076,6 +2076,7 @@ export class TranslationServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/test/gapic_translation_service_v3beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/test/gapic_translation_service_v3beta1.ts.baseline
index fc685c940bb9..953f4a83e4ff 100644
--- a/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/test/gapic_translation_service_v3beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/test/gapic_translation_service_v3beta1.ts.baseline
@@ -314,6 +314,7 @@ describe('v3beta1.TranslationServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -331,6 +332,7 @@ describe('v3beta1.TranslationServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/translate/src/v3beta1/translation_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/translate/src/v3beta1/translation_service_client.ts.baseline
index fb13a719454f..76b74f4bd748 100644
--- a/core/generator/gapic-generator-typescript/baselines/translate/src/v3beta1/translation_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/translate/src/v3beta1/translation_service_client.ts.baseline
@@ -2054,6 +2054,7 @@ export class TranslationServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/translate/test/gapic_translation_service_v3beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/translate/test/gapic_translation_service_v3beta1.ts.baseline
index c783079a6b50..f5a7478c6740 100644
--- a/core/generator/gapic-generator-typescript/baselines/translate/test/gapic_translation_service_v3beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/translate/test/gapic_translation_service_v3beta1.ts.baseline
@@ -303,6 +303,7 @@ describe('v3beta1.TranslationServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -320,6 +321,7 @@ describe('v3beta1.TranslationServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/src/v1/video_intelligence_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/src/v1/video_intelligence_service_client.ts.baseline
index c492d9c70fbb..798dc9db9bab 100644
--- a/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/src/v1/video_intelligence_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/src/v1/video_intelligence_service_client.ts.baseline
@@ -623,6 +623,7 @@ export class VideoIntelligenceServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/test/gapic_video_intelligence_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/test/gapic_video_intelligence_service_v1.ts.baseline
index 2393f6a8e02b..cfefcfd51e8d 100644
--- a/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/test/gapic_video_intelligence_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/test/gapic_video_intelligence_service_v1.ts.baseline
@@ -247,6 +247,7 @@ describe('v1.VideoIntelligenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -264,6 +265,7 @@ describe('v1.VideoIntelligenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/baselines/videointelligence/src/v1/video_intelligence_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/videointelligence/src/v1/video_intelligence_service_client.ts.baseline
index 813a9652b7c9..4518daf442c9 100644
--- a/core/generator/gapic-generator-typescript/baselines/videointelligence/src/v1/video_intelligence_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/videointelligence/src/v1/video_intelligence_service_client.ts.baseline
@@ -601,6 +601,7 @@ export class VideoIntelligenceServiceClient {
         this._terminated = true;
         stub.close();
         void this.operationsClient.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/videointelligence/test/gapic_video_intelligence_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/videointelligence/test/gapic_video_intelligence_service_v1.ts.baseline
index 115fdb8ce672..886a5d348e35 100644
--- a/core/generator/gapic-generator-typescript/baselines/videointelligence/test/gapic_video_intelligence_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/videointelligence/test/gapic_video_intelligence_service_v1.ts.baseline
@@ -236,6 +236,7 @@ describe('v1.VideoIntelligenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
@@ -253,6 +254,7 @@ describe('v1.VideoIntelligenceServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
         .catch(err => {
           throw err;
diff --git a/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/_util.njk b/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/_util.njk
index daa639d82edc..55ef859d5610 100644
--- a/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/_util.njk
+++ b/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/_util.njk
@@ -265,7 +265,7 @@ request.{{ oneComment.paramName.toCamelCase() }}
     options.otherArgs.headers = options.otherArgs.headers || {};
 {#- if dynamic routing annotation exists and is non empty, then send dynamic routing header #}
 {%- if method.dynamicRoutingRequestParams.length > 0 %}
-    let routingParameter = {};
+    const routingParameter = {};
 {%- for paramArray in method.dynamicRoutingRequestParams %}
   {%- for param in paramArray %}
     {
diff --git a/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/src/$version/$service_client.ts.njk b/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/src/$version/$service_client.ts.njk
index 82dded752187..43eb887a150e 100644
--- a/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/src/$version/$service_client.ts.njk
+++ b/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/src/$version/$service_client.ts.njk
@@ -1183,6 +1183,7 @@ export class {{ service.name }}Client {
         {%- if service.longRunning.length > 0 or service.LongRunningOperationsMixin > 0 %}
         void this.operationsClient.close();
         {%- endif %}
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk b/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk
index a17e90c9fcec..c39385b9f2e5 100644
--- a/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk
+++ b/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk
@@ -326,6 +326,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
             assert(client.{{ service.name.toCamelCase() }}Stub);
             client.{{ id.get("close") }}().then(() => {
                 done();
+                return;
             }).catch(err => {throw err});
         });
 
@@ -334,6 +335,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
             assert.strictEqual(client.{{ service.name.toCamelCase() }}Stub, undefined);
             client.{{ id.get("close") }}().then(() => {
                 done();
+                return;
             }).catch(err => {throw err});
         });
 
@@ -1279,7 +1281,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
                         } else {
                             resolve(result);
                         }
-                    });
+                    }).catch(err => {throw err});
             });
             const response = await promise;
             {%- if method.options and method.options.deprecated %}
diff --git a/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/_util.njk b/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/_util.njk
index 1f88cc4a9f38..b83b11c0645f 100644
--- a/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/_util.njk
+++ b/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/_util.njk
@@ -265,7 +265,7 @@ request.{{ oneComment.paramName.toCamelCase() }}
     options.otherArgs.headers = options.otherArgs.headers || {};
 {#- if dynamic routing annotation exists and is non empty, then send dynamic routing header #}
 {%- if method.dynamicRoutingRequestParams.length > 0 %}
-    let routingParameter = {};
+    const routingParameter = {};
 {%- for paramArray in method.dynamicRoutingRequestParams %}
   {%- for param in paramArray %}
     {
diff --git a/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/src/$version/$service_client.ts.njk b/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/src/$version/$service_client.ts.njk
index e61b45594482..9b5f970b12ae 100644
--- a/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/src/$version/$service_client.ts.njk
+++ b/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/src/$version/$service_client.ts.njk
@@ -1190,6 +1190,7 @@ export class {{ service.name }}Client {
         {%- if service.longRunning.length > 0 or service.LongRunningOperationsMixin > 0 %}
         void this.operationsClient.close();
         {%- endif %}
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk b/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk
index 8ab598a531e9..087e9fbd2505 100644
--- a/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk
+++ b/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk
@@ -333,6 +333,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
             assert(client.{{ service.name.toCamelCase() }}Stub);
             client.{{ id.get("close") }}().then(() => {
                 done();
+                return;
             }).catch(err => {throw err});
         });
 
@@ -341,6 +342,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
             assert.strictEqual(client.{{ service.name.toCamelCase() }}Stub, undefined);
             client.{{ id.get("close") }}().then(() => {
                 done();
+                return;
             }).catch(err => {throw err});
         });
 
@@ -1285,7 +1287,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
                         } else {
                             resolve(result);
                         }
-                    });
+                    }).catch(err => {throw err});
             });
             const response = await promise;
             {%- if method.options and method.options.deprecated %}

From c7872473adff2e965d0b87e607cc1226f7e0b951 Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Wed, 23 Sep 2026 19:37:03 +0000
Subject: [PATCH 2/3] fix(generator): use .catch(reject) in mixin callback
 tests

Throwing from the .catch handler inside a new Promise executor leaves the
outer promise pending; pass reject instead. Applied to all three mixin
callback tests (IAM, Locations, operations) in cjs and esm.
---
 ...pic_duplicate_methods_test_service_v1.ts.baseline | 12 +++---------
 ...pic_duplicate_methods_test_service_v1.ts.baseline | 12 +++---------
 .../test/gapic_key_management_service_v1.ts.baseline | 12 +++---------
 .../test/gapic_key_management_service_v1.ts.baseline | 12 +++---------
 .../esm/test/gapic_cloud_redis_v1beta1.ts.baseline   | 12 +++---------
 .../redis/test/gapic_cloud_redis_v1beta1.ts.baseline | 12 +++---------
 .../test/gapic_$service_$version.ts.njk              |  6 +++---
 .../esm/test/gapic_$service_$version.ts.njk          |  6 +++---
 8 files changed, 24 insertions(+), 60 deletions(-)

diff --git a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline
index b7a3b16f9def..10e29b8c54d1 100644
--- a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline
@@ -990,9 +990,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -1112,9 +1110,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -1234,9 +1230,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
diff --git a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline
index bf984ae24aaf..3ee6cd4e5ae6 100644
--- a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline
@@ -979,9 +979,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -1101,9 +1099,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -1223,9 +1219,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
diff --git a/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline
index d89d4d9da2bd..6b7e7aafd2b5 100644
--- a/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline
@@ -4309,9 +4309,7 @@ describe('v1.KeyManagementServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -4422,9 +4420,7 @@ describe('v1.KeyManagementServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -4538,9 +4534,7 @@ describe('v1.KeyManagementServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
diff --git a/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline
index 488bc6058592..16fb52978703 100644
--- a/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline
@@ -4298,9 +4298,7 @@ describe('v1.KeyManagementServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -4411,9 +4409,7 @@ describe('v1.KeyManagementServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -4527,9 +4523,7 @@ describe('v1.KeyManagementServiceClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
diff --git a/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline
index 988ba98126c7..9e85580ce628 100644
--- a/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline
@@ -2014,9 +2014,7 @@ describe('v1beta1.CloudRedisClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -2098,9 +2096,7 @@ describe('v1beta1.CloudRedisClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -2182,9 +2178,7 @@ describe('v1beta1.CloudRedisClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
diff --git a/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline
index 771c75747f7b..bfe18af20135 100644
--- a/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline
@@ -2003,9 +2003,7 @@ describe('v1beta1.CloudRedisClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -2087,9 +2085,7 @@ describe('v1beta1.CloudRedisClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
@@ -2171,9 +2167,7 @@ describe('v1beta1.CloudRedisClient', () => {
               }
             },
           )
-          .catch(err => {
-            throw err;
-          });
+          .catch(reject);
       });
       const response = await promise;
       assert.deepStrictEqual(response, expectedResponse);
diff --git a/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk b/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk
index c39385b9f2e5..5e83e829585e 100644
--- a/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk
+++ b/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk
@@ -1169,7 +1169,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
                         } else {
                             resolve(result);
                         }
-                    }).catch(err => {throw err});
+                    }).catch(reject);
             });
             const response = await promise;
             {%- if method.options and method.options.deprecated %}
@@ -1281,7 +1281,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
                         } else {
                             resolve(result);
                         }
-                    }).catch(err => {throw err});
+                    }).catch(reject);
             });
             const response = await promise;
             {%- if method.options and method.options.deprecated %}
@@ -1470,7 +1470,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
                         } else {
                             resolve(result);
                         }
-                    }).catch(err => {throw err});
+                    }).catch(reject);
             });
             const response = await promise;
             {%- if method.options and method.options.deprecated %}
diff --git a/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk b/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk
index 087e9fbd2505..8908e79cac25 100644
--- a/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk
+++ b/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk
@@ -1175,7 +1175,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
                         } else {
                             resolve(result);
                         }
-                    }).catch(err => {throw err});
+                    }).catch(reject);
             });
             const response = await promise;
             {%- if method.options and method.options.deprecated %}
@@ -1287,7 +1287,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
                         } else {
                             resolve(result);
                         }
-                    }).catch(err => {throw err});
+                    }).catch(reject);
             });
             const response = await promise;
             {%- if method.options and method.options.deprecated %}
@@ -1476,7 +1476,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
                         } else {
                             resolve(result);
                         }
-                    }).catch(err => {throw err});
+                    }).catch(reject);
             });
             const response = await promise;
             {%- if method.options and method.options.deprecated %}

From 2c376d6f7f89f6821399663da07f45c4efe26a2d Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Tue, 13 Oct 2026 16:15:40 +0000
Subject: [PATCH 3/3] fix(generator): use .catch(done) in close() callback
 tests and update baselines

---
 .../esm/test/gapic_asset_service_v1.ts.baseline        |  8 ++------
 .../asset/test/gapic_asset_service_v1.ts.baseline      |  8 ++------
 .../test/gapic_big_query_storage_v1beta1.ts.baseline   |  8 ++------
 .../test/gapic_big_query_storage_v1beta1.ts.baseline   |  8 ++------
 .../esm/test/gapic_dataset_service_v2.ts.baseline      |  8 ++------
 .../esm/test/gapic_job_service_v2.ts.baseline          |  8 ++------
 .../esm/test/gapic_model_service_v2.ts.baseline        |  8 ++------
 .../esm/test/gapic_project_service_v2.ts.baseline      |  8 ++------
 .../esm/test/gapic_routine_service_v2.ts.baseline      |  8 ++------
 .../gapic_row_access_policy_service_v2.ts.baseline     |  8 ++------
 .../esm/test/gapic_table_service_v2.ts.baseline        |  8 ++------
 .../test/gapic_dataset_service_v2.ts.baseline          |  8 ++------
 .../bigquery-v2/test/gapic_job_service_v2.ts.baseline  |  8 ++------
 .../test/gapic_model_service_v2.ts.baseline            |  8 ++------
 .../test/gapic_project_service_v2.ts.baseline          |  8 ++------
 .../test/gapic_routine_service_v2.ts.baseline          |  8 ++------
 .../gapic_row_access_policy_service_v2.ts.baseline     |  8 ++------
 .../test/gapic_table_service_v2.ts.baseline            |  8 ++------
 .../esm/test/gapic_addresses_v1.ts.baseline            |  8 ++------
 .../esm/test/gapic_region_operations_v1.ts.baseline    |  8 ++------
 .../compute/test/gapic_addresses_v1.ts.baseline        |  8 ++------
 .../test/gapic_region_operations_v1.ts.baseline        |  8 ++------
 .../esm/test/gapic_compliance_v1beta1.ts.baseline      |  8 ++------
 .../esm/test/gapic_echo_v1beta1.ts.baseline            |  8 ++------
 .../esm/test/gapic_identity_v1beta1.ts.baseline        |  8 ++------
 .../esm/test/gapic_messaging_v1beta1.ts.baseline       |  8 ++------
 .../test/gapic_sequence_service_v1beta1.ts.baseline    |  8 ++------
 .../esm/test/gapic_testing_v1beta1.ts.baseline         |  8 ++------
 .../test/gapic_compliance_v1beta1.ts.baseline          |  8 ++------
 .../test/gapic_echo_v1beta1.ts.baseline                |  8 ++------
 .../test/gapic_identity_v1beta1.ts.baseline            |  8 ++------
 .../test/gapic_messaging_v1beta1.ts.baseline           |  8 ++------
 .../test/gapic_sequence_service_v1beta1.ts.baseline    |  8 ++------
 .../test/gapic_testing_v1beta1.ts.baseline             |  8 ++------
 .../dlp-esm/esm/test/gapic_dlp_service_v2.ts.baseline  |  8 ++------
 .../dlp/test/gapic_dlp_service_v2.ts.baseline          |  8 ++------
 ...gapic_duplicate_methods_test_service_v1.ts.baseline |  8 ++------
 ...gapic_duplicate_methods_test_service_v1.ts.baseline |  8 ++------
 .../test/gapic_key_management_service_v1.ts.baseline   |  8 ++------
 .../test/gapic_key_management_service_v1.ts.baseline   |  8 ++------
 .../esm/test/gapic_config_service_v2_v2.ts.baseline    |  8 ++------
 .../esm/test/gapic_logging_service_v2_v2.ts.baseline   |  8 ++------
 .../esm/test/gapic_metrics_service_v2_v2.ts.baseline   |  8 ++------
 .../test/gapic_config_service_v2_v2.ts.baseline        |  8 ++------
 .../test/gapic_logging_service_v2_v2.ts.baseline       |  8 ++------
 .../test/gapic_metrics_service_v2_v2.ts.baseline       |  8 ++------
 .../esm/test/gapic_alert_policy_service_v3.ts.baseline |  8 ++------
 .../esm/test/gapic_group_service_v3.ts.baseline        |  8 ++------
 .../esm/test/gapic_metric_service_v3.ts.baseline       |  8 ++------
 .../gapic_notification_channel_service_v3.ts.baseline  |  8 ++------
 .../gapic_service_monitoring_service_v3.ts.baseline    |  8 ++------
 .../esm/test/gapic_uptime_check_service_v3.ts.baseline |  8 ++------
 .../test/gapic_alert_policy_service_v3.ts.baseline     |  8 ++------
 .../monitoring/test/gapic_group_service_v3.ts.baseline |  8 ++------
 .../test/gapic_metric_service_v3.ts.baseline           |  8 ++------
 .../gapic_notification_channel_service_v3.ts.baseline  |  8 ++------
 .../gapic_service_monitoring_service_v3.ts.baseline    |  8 ++------
 .../test/gapic_uptime_check_service_v3.ts.baseline     |  8 ++------
 .../esm/test/gapic_naming_v1beta1.ts.baseline          |  8 ++------
 .../naming/test/gapic_naming_v1beta1.ts.baseline       |  8 ++------
 .../esm/test/gapic_cloud_redis_v1beta1.ts.baseline     |  8 ++------
 .../redis/test/gapic_cloud_redis_v1beta1.ts.baseline   |  8 ++------
 .../src/v1/resumable_upload_service_client.ts.baseline |  1 +
 .../test/gapic_resumable_upload_service_v1.ts.baseline | 10 ++++------
 .../src/v1/resumable_upload_service_client.ts.baseline |  1 +
 .../test/gapic_resumable_upload_service_v1.ts.baseline | 10 ++++------
 .../test/gapic_analytics_service_v2alpha.ts.baseline   |  8 ++------
 .../esm/test/gapic_branch_service_v2alpha.ts.baseline  |  8 ++------
 .../esm/test/gapic_catalog_service_v2alpha.ts.baseline |  8 ++------
 .../test/gapic_completion_service_v2alpha.ts.baseline  |  8 ++------
 .../esm/test/gapic_control_service_v2alpha.ts.baseline |  8 ++------
 ...c_conversational_search_service_v2alpha.ts.baseline |  8 ++------
 ...pic_generative_question_service_v2alpha.ts.baseline |  8 ++------
 ...ant_center_account_link_service_v2alpha.ts.baseline |  8 ++------
 .../esm/test/gapic_model_service_v2alpha.ts.baseline   |  8 ++------
 .../test/gapic_prediction_service_v2alpha.ts.baseline  |  8 ++------
 .../esm/test/gapic_product_service_v2alpha.ts.baseline |  8 ++------
 .../esm/test/gapic_project_service_v2alpha.ts.baseline |  8 ++------
 .../esm/test/gapic_search_service_v2alpha.ts.baseline  |  8 ++------
 .../gapic_serving_config_service_v2alpha.ts.baseline   |  8 ++------
 .../test/gapic_user_event_service_v2alpha.ts.baseline  |  8 ++------
 .../test/gapic_analytics_service_v2alpha.ts.baseline   |  8 ++------
 .../test/gapic_branch_service_v2alpha.ts.baseline      |  8 ++------
 .../test/gapic_catalog_service_v2alpha.ts.baseline     |  8 ++------
 .../test/gapic_completion_service_v2alpha.ts.baseline  |  8 ++------
 .../test/gapic_control_service_v2alpha.ts.baseline     |  8 ++------
 ...c_conversational_search_service_v2alpha.ts.baseline |  8 ++------
 ...pic_generative_question_service_v2alpha.ts.baseline |  8 ++------
 ...ant_center_account_link_service_v2alpha.ts.baseline |  8 ++------
 .../test/gapic_model_service_v2alpha.ts.baseline       |  8 ++------
 .../test/gapic_prediction_service_v2alpha.ts.baseline  |  8 ++------
 .../test/gapic_product_service_v2alpha.ts.baseline     |  8 ++------
 .../test/gapic_project_service_v2alpha.ts.baseline     |  8 ++------
 .../test/gapic_search_service_v2alpha.ts.baseline      |  8 ++------
 .../gapic_serving_config_service_v2alpha.ts.baseline   |  8 ++------
 .../test/gapic_user_event_service_v2alpha.ts.baseline  |  8 ++------
 .../esm/test/gapic_test_service_v1.ts.baseline         |  8 ++------
 .../routingtest/test/gapic_test_service_v1.ts.baseline |  8 ++------
 .../esm/test/gapic_compliance_v1beta1.ts.baseline      |  8 ++------
 .../esm/test/gapic_echo_v1beta1.ts.baseline            |  8 ++------
 .../esm/test/gapic_identity_v1beta1.ts.baseline        |  8 ++------
 .../esm/test/gapic_messaging_v1beta1.ts.baseline       |  8 ++------
 .../test/gapic_sequence_service_v1beta1.ts.baseline    |  8 ++------
 .../esm/test/gapic_testing_v1beta1.ts.baseline         |  8 ++------
 .../esm/test/gapic_echo_v1beta1.ts.baseline            |  8 ++------
 .../test/gapic_echo_v1beta1.ts.baseline                |  8 ++------
 .../showcase/test/gapic_compliance_v1beta1.ts.baseline |  8 ++------
 .../showcase/test/gapic_echo_v1beta1.ts.baseline       |  8 ++------
 .../showcase/test/gapic_identity_v1beta1.ts.baseline   |  8 ++------
 .../showcase/test/gapic_messaging_v1beta1.ts.baseline  |  8 ++------
 .../test/gapic_sequence_service_v1beta1.ts.baseline    |  8 ++------
 .../showcase/test/gapic_testing_v1beta1.ts.baseline    |  8 ++------
 .../esm/test/gapic_cloud_tasks_v2.ts.baseline          |  8 ++------
 .../tasks/test/gapic_cloud_tasks_v2.ts.baseline        |  8 ++------
 .../esm/test/gapic_text_to_speech_v1.ts.baseline       |  8 ++------
 .../test/gapic_text_to_speech_v1.ts.baseline           |  8 ++------
 .../test/gapic_translation_service_v3beta1.ts.baseline |  8 ++------
 .../test/gapic_translation_service_v3beta1.ts.baseline |  8 ++------
 .../gapic_video_intelligence_service_v1.ts.baseline    |  8 ++------
 .../gapic_video_intelligence_service_v1.ts.baseline    |  8 ++------
 .../test/gapic_$service_$version.ts.njk                |  4 ++--
 .../esm/test/gapic_$service_$version.ts.njk            |  4 ++--
 122 files changed, 246 insertions(+), 712 deletions(-)

diff --git a/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/test/gapic_asset_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/test/gapic_asset_service_v1.ts.baseline
index 9cde74ade06a..ab0fcbcb613a 100644
--- a/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/test/gapic_asset_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/asset-esm/esm/test/gapic_asset_service_v1.ts.baseline
@@ -242,9 +242,7 @@ describe('v1.AssetServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -259,9 +257,7 @@ describe('v1.AssetServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/asset/test/gapic_asset_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/asset/test/gapic_asset_service_v1.ts.baseline
index b61105b1e90a..4df7cbc1a3d5 100644
--- a/core/generator/gapic-generator-typescript/baselines/asset/test/gapic_asset_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/asset/test/gapic_asset_service_v1.ts.baseline
@@ -231,9 +231,7 @@ describe('v1.AssetServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -248,9 +246,7 @@ describe('v1.AssetServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/test/gapic_big_query_storage_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/test/gapic_big_query_storage_v1beta1.ts.baseline
index 06bc214cd8a9..c3ef5049100d 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/test/gapic_big_query_storage_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-storage-esm/esm/test/gapic_big_query_storage_v1beta1.ts.baseline
@@ -238,9 +238,7 @@ describe('v1beta1.BigQueryStorageClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -255,9 +253,7 @@ describe('v1beta1.BigQueryStorageClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-storage/test/gapic_big_query_storage_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-storage/test/gapic_big_query_storage_v1beta1.ts.baseline
index c2d8f16f7845..d10fa84a6dfb 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-storage/test/gapic_big_query_storage_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-storage/test/gapic_big_query_storage_v1beta1.ts.baseline
@@ -227,9 +227,7 @@ describe('v1beta1.BigQueryStorageClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -244,9 +242,7 @@ describe('v1beta1.BigQueryStorageClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_dataset_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_dataset_service_v2.ts.baseline
index 76fb44a02b4f..bdd044e09b6c 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_dataset_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_dataset_service_v2.ts.baseline
@@ -273,9 +273,7 @@ describe('v2.DatasetServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -290,9 +288,7 @@ describe('v2.DatasetServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_job_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_job_service_v2.ts.baseline
index f35baebe0fcd..051cf93b4424 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_job_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_job_service_v2.ts.baseline
@@ -271,9 +271,7 @@ describe('v2.JobServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -288,9 +286,7 @@ describe('v2.JobServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_model_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_model_service_v2.ts.baseline
index 7cd2817eb91d..2b03d1ec2aeb 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_model_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_model_service_v2.ts.baseline
@@ -273,9 +273,7 @@ describe('v2.ModelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -290,9 +288,7 @@ describe('v2.ModelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_project_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_project_service_v2.ts.baseline
index a4debcaad21d..c1b20ad5e2ee 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_project_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_project_service_v2.ts.baseline
@@ -210,9 +210,7 @@ describe('v2.ProjectServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -227,9 +225,7 @@ describe('v2.ProjectServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_routine_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_routine_service_v2.ts.baseline
index a05af52ba6bf..d33e6c74c703 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_routine_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_routine_service_v2.ts.baseline
@@ -273,9 +273,7 @@ describe('v2.RoutineServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -290,9 +288,7 @@ describe('v2.RoutineServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_row_access_policy_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_row_access_policy_service_v2.ts.baseline
index 78296d01919d..931306e2a09e 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_row_access_policy_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_row_access_policy_service_v2.ts.baseline
@@ -286,9 +286,7 @@ describe('v2.RowAccessPolicyServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -304,9 +302,7 @@ describe('v2.RowAccessPolicyServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_table_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_table_service_v2.ts.baseline
index 020f9414d188..f37d1337456b 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_table_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2-esm/esm/test/gapic_table_service_v2.ts.baseline
@@ -273,9 +273,7 @@ describe('v2.TableServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -290,9 +288,7 @@ describe('v2.TableServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_dataset_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_dataset_service_v2.ts.baseline
index 2b3eaeb6e759..9b5d2958f06e 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_dataset_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_dataset_service_v2.ts.baseline
@@ -262,9 +262,7 @@ describe('v2.DatasetServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -279,9 +277,7 @@ describe('v2.DatasetServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_job_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_job_service_v2.ts.baseline
index c4fc31d5dec6..7b4006617e63 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_job_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_job_service_v2.ts.baseline
@@ -260,9 +260,7 @@ describe('v2.JobServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -277,9 +275,7 @@ describe('v2.JobServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_model_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_model_service_v2.ts.baseline
index ceee71b9a639..1d7fedf04fcb 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_model_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_model_service_v2.ts.baseline
@@ -262,9 +262,7 @@ describe('v2.ModelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -279,9 +277,7 @@ describe('v2.ModelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_project_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_project_service_v2.ts.baseline
index d5b74accb4c5..f1af1adcd64c 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_project_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_project_service_v2.ts.baseline
@@ -199,9 +199,7 @@ describe('v2.ProjectServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -216,9 +214,7 @@ describe('v2.ProjectServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_routine_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_routine_service_v2.ts.baseline
index efa6c8983dba..cbaad4ad9a98 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_routine_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_routine_service_v2.ts.baseline
@@ -262,9 +262,7 @@ describe('v2.RoutineServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -279,9 +277,7 @@ describe('v2.RoutineServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_row_access_policy_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_row_access_policy_service_v2.ts.baseline
index 69a60627fab3..65e8db4ef8f3 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_row_access_policy_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_row_access_policy_service_v2.ts.baseline
@@ -275,9 +275,7 @@ describe('v2.RowAccessPolicyServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -293,9 +291,7 @@ describe('v2.RowAccessPolicyServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_table_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_table_service_v2.ts.baseline
index 5e3bf93ef666..367e0cae6726 100644
--- a/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_table_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/bigquery-v2/test/gapic_table_service_v2.ts.baseline
@@ -262,9 +262,7 @@ describe('v2.TableServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -279,9 +277,7 @@ describe('v2.TableServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_addresses_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_addresses_v1.ts.baseline
index b950ca904db8..6f3a12487ef1 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_addresses_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_addresses_v1.ts.baseline
@@ -284,9 +284,7 @@ describe('v1.AddressesClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -301,9 +299,7 @@ describe('v1.AddressesClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_region_operations_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_region_operations_v1.ts.baseline
index e799b69a5d0c..cac527bac61f 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_region_operations_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute-esm/esm/test/gapic_region_operations_v1.ts.baseline
@@ -223,9 +223,7 @@ describe('v1.RegionOperationsClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -240,9 +238,7 @@ describe('v1.RegionOperationsClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_addresses_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_addresses_v1.ts.baseline
index a36f306abcb8..bdc011f62d70 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_addresses_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_addresses_v1.ts.baseline
@@ -273,9 +273,7 @@ describe('v1.AddressesClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -290,9 +288,7 @@ describe('v1.AddressesClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_region_operations_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_region_operations_v1.ts.baseline
index ce61791282f3..5a3606835410 100644
--- a/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_region_operations_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/compute/test/gapic_region_operations_v1.ts.baseline
@@ -212,9 +212,7 @@ describe('v1.RegionOperationsClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -229,9 +227,7 @@ describe('v1.RegionOperationsClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_compliance_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
index 20a3891b7d93..a2199efabb11 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
@@ -163,9 +163,7 @@ describe('v1beta1.ComplianceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -180,9 +178,7 @@ describe('v1beta1.ComplianceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_echo_v1beta1.ts.baseline
index 0d5540b77059..196325be9130 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_echo_v1beta1.ts.baseline
@@ -306,9 +306,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -323,9 +321,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_identity_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_identity_v1beta1.ts.baseline
index 1cb9cb307920..5e58be660335 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_identity_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_identity_v1beta1.ts.baseline
@@ -224,9 +224,7 @@ describe('v1beta1.IdentityClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -241,9 +239,7 @@ describe('v1beta1.IdentityClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_messaging_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
index ffd4fdf763e8..a7cfa94622fb 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
@@ -306,9 +306,7 @@ describe('v1beta1.MessagingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -323,9 +321,7 @@ describe('v1beta1.MessagingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
index b9e4f3e9097c..822e8c312493 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
@@ -163,9 +163,7 @@ describe('v1beta1.SequenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -180,9 +178,7 @@ describe('v1beta1.SequenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_testing_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_testing_v1beta1.ts.baseline
index 14b0f953fd35..77efcb0e588c 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_testing_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test-esm/esm/test/gapic_testing_v1beta1.ts.baseline
@@ -224,9 +224,7 @@ describe('v1beta1.TestingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -241,9 +239,7 @@ describe('v1beta1.TestingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_compliance_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_compliance_v1beta1.ts.baseline
index 2ee428d6bdb7..6bdf50e04168 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_compliance_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_compliance_v1beta1.ts.baseline
@@ -152,9 +152,7 @@ describe('v1beta1.ComplianceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -169,9 +167,7 @@ describe('v1beta1.ComplianceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_echo_v1beta1.ts.baseline
index 57178731bc27..ee2f30ef8534 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_echo_v1beta1.ts.baseline
@@ -295,9 +295,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -312,9 +310,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_identity_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_identity_v1beta1.ts.baseline
index f32f7f9210b5..a8257690745a 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_identity_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_identity_v1beta1.ts.baseline
@@ -213,9 +213,7 @@ describe('v1beta1.IdentityClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -230,9 +228,7 @@ describe('v1beta1.IdentityClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_messaging_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_messaging_v1beta1.ts.baseline
index 6bf50c4a7ece..187ad4e277a3 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_messaging_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_messaging_v1beta1.ts.baseline
@@ -295,9 +295,7 @@ describe('v1beta1.MessagingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -312,9 +310,7 @@ describe('v1beta1.MessagingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_sequence_service_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_sequence_service_v1beta1.ts.baseline
index 8fed411f2e64..f4256cba7d3a 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_sequence_service_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_sequence_service_v1beta1.ts.baseline
@@ -152,9 +152,7 @@ describe('v1beta1.SequenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -169,9 +167,7 @@ describe('v1beta1.SequenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_testing_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_testing_v1beta1.ts.baseline
index 75f225c4b150..b7ae75c8ec5a 100644
--- a/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_testing_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/disable-packing-test/test/gapic_testing_v1beta1.ts.baseline
@@ -213,9 +213,7 @@ describe('v1beta1.TestingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -230,9 +228,7 @@ describe('v1beta1.TestingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/test/gapic_dlp_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/test/gapic_dlp_service_v2.ts.baseline
index 74ec0ac2ff1f..095ee7031b5e 100644
--- a/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/test/gapic_dlp_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/dlp-esm/esm/test/gapic_dlp_service_v2.ts.baseline
@@ -271,9 +271,7 @@ describe('v2.DlpServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -288,9 +286,7 @@ describe('v2.DlpServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/dlp/test/gapic_dlp_service_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/dlp/test/gapic_dlp_service_v2.ts.baseline
index af75ba099eb2..bcb7f86ead3c 100644
--- a/core/generator/gapic-generator-typescript/baselines/dlp/test/gapic_dlp_service_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/dlp/test/gapic_dlp_service_v2.ts.baseline
@@ -260,9 +260,7 @@ describe('v2.DlpServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -277,9 +275,7 @@ describe('v2.DlpServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline
index 10e29b8c54d1..4f1586b1675e 100644
--- a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test-esm/esm/test/gapic_duplicate_methods_test_service_v1.ts.baseline
@@ -295,9 +295,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -315,9 +313,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline
index 3ee6cd4e5ae6..e002eb2f66cc 100644
--- a/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/duplicate_methods_test/test/gapic_duplicate_methods_test_service_v1.ts.baseline
@@ -284,9 +284,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -304,9 +302,7 @@ describe('v1.DuplicateMethodsTestServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline
index 6b7e7aafd2b5..e3ed1bc147a3 100644
--- a/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/kms-esm/esm/test/gapic_key_management_service_v1.ts.baseline
@@ -284,9 +284,7 @@ describe('v1.KeyManagementServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -302,9 +300,7 @@ describe('v1.KeyManagementServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline
index 16fb52978703..9f633782d0f5 100644
--- a/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/kms/test/gapic_key_management_service_v1.ts.baseline
@@ -273,9 +273,7 @@ describe('v1.KeyManagementServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -291,9 +289,7 @@ describe('v1.KeyManagementServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_config_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_config_service_v2_v2.ts.baseline
index c11f2c70cc20..de5586272f3b 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_config_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_config_service_v2_v2.ts.baseline
@@ -305,9 +305,7 @@ describe('v2.ConfigServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -322,9 +320,7 @@ describe('v2.ConfigServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_logging_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_logging_service_v2_v2.ts.baseline
index 91fdb2c51e0f..a50631128a08 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_logging_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_logging_service_v2_v2.ts.baseline
@@ -287,9 +287,7 @@ describe('v2.LoggingServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -304,9 +302,7 @@ describe('v2.LoggingServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_metrics_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_metrics_service_v2_v2.ts.baseline
index e0ee3b493df1..0f01abfd1644 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_metrics_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging-esm/esm/test/gapic_metrics_service_v2_v2.ts.baseline
@@ -273,9 +273,7 @@ describe('v2.MetricsServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -290,9 +288,7 @@ describe('v2.MetricsServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_config_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_config_service_v2_v2.ts.baseline
index 0b0614495fac..112e8056fdec 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_config_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_config_service_v2_v2.ts.baseline
@@ -294,9 +294,7 @@ describe('v2.ConfigServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -311,9 +309,7 @@ describe('v2.ConfigServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_logging_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_logging_service_v2_v2.ts.baseline
index 22524ce75e5e..2120ab2d6e4b 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_logging_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_logging_service_v2_v2.ts.baseline
@@ -276,9 +276,7 @@ describe('v2.LoggingServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -293,9 +291,7 @@ describe('v2.LoggingServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_metrics_service_v2_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_metrics_service_v2_v2.ts.baseline
index 867b1dffc732..3d56b611f617 100644
--- a/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_metrics_service_v2_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/logging/test/gapic_metrics_service_v2_v2.ts.baseline
@@ -262,9 +262,7 @@ describe('v2.MetricsServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -279,9 +277,7 @@ describe('v2.MetricsServiceV2Client', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_alert_policy_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_alert_policy_service_v3.ts.baseline
index 50c96488cd6d..6eecf7294139 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_alert_policy_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_alert_policy_service_v3.ts.baseline
@@ -275,9 +275,7 @@ describe('v3.AlertPolicyServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -292,9 +290,7 @@ describe('v3.AlertPolicyServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_group_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_group_service_v3.ts.baseline
index 1620bfa2b86f..76685f6c6747 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_group_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_group_service_v3.ts.baseline
@@ -273,9 +273,7 @@ describe('v3.GroupServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -290,9 +288,7 @@ describe('v3.GroupServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_metric_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_metric_service_v3.ts.baseline
index d68422e7264e..d2e0115c704e 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_metric_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_metric_service_v3.ts.baseline
@@ -273,9 +273,7 @@ describe('v3.MetricServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -290,9 +288,7 @@ describe('v3.MetricServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_notification_channel_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_notification_channel_service_v3.ts.baseline
index 3ee187438f3b..22125d6c5d09 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_notification_channel_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_notification_channel_service_v3.ts.baseline
@@ -292,9 +292,7 @@ describe('v3.NotificationChannelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -312,9 +310,7 @@ describe('v3.NotificationChannelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_service_monitoring_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_service_monitoring_service_v3.ts.baseline
index f2afe6d80703..6af5a6ef4dd6 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_service_monitoring_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_service_monitoring_service_v3.ts.baseline
@@ -286,9 +286,7 @@ describe('v3.ServiceMonitoringServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -304,9 +302,7 @@ describe('v3.ServiceMonitoringServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_uptime_check_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_uptime_check_service_v3.ts.baseline
index b351af6e64a4..446242b075de 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_uptime_check_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring-esm/esm/test/gapic_uptime_check_service_v3.ts.baseline
@@ -275,9 +275,7 @@ describe('v3.UptimeCheckServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -292,9 +290,7 @@ describe('v3.UptimeCheckServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_alert_policy_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_alert_policy_service_v3.ts.baseline
index 24bf1707e142..b0bcf5220cec 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_alert_policy_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_alert_policy_service_v3.ts.baseline
@@ -264,9 +264,7 @@ describe('v3.AlertPolicyServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -281,9 +279,7 @@ describe('v3.AlertPolicyServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_group_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_group_service_v3.ts.baseline
index e6f11585139e..911398e3cffa 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_group_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_group_service_v3.ts.baseline
@@ -262,9 +262,7 @@ describe('v3.GroupServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -279,9 +277,7 @@ describe('v3.GroupServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_metric_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_metric_service_v3.ts.baseline
index e62d5170f4dc..fabcc8f880d7 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_metric_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_metric_service_v3.ts.baseline
@@ -262,9 +262,7 @@ describe('v3.MetricServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -279,9 +277,7 @@ describe('v3.MetricServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_notification_channel_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_notification_channel_service_v3.ts.baseline
index d8be2e56c529..eac24ebfbf03 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_notification_channel_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_notification_channel_service_v3.ts.baseline
@@ -281,9 +281,7 @@ describe('v3.NotificationChannelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -301,9 +299,7 @@ describe('v3.NotificationChannelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_service_monitoring_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_service_monitoring_service_v3.ts.baseline
index 64e9f88ceaf5..321cd9e43d6e 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_service_monitoring_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_service_monitoring_service_v3.ts.baseline
@@ -275,9 +275,7 @@ describe('v3.ServiceMonitoringServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -293,9 +291,7 @@ describe('v3.ServiceMonitoringServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_uptime_check_service_v3.ts.baseline b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_uptime_check_service_v3.ts.baseline
index 305637d15e43..7ca6bf7043cb 100644
--- a/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_uptime_check_service_v3.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/monitoring/test/gapic_uptime_check_service_v3.ts.baseline
@@ -264,9 +264,7 @@ describe('v3.UptimeCheckServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -281,9 +279,7 @@ describe('v3.UptimeCheckServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/test/gapic_naming_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/test/gapic_naming_v1beta1.ts.baseline
index ee79ada183c0..d241d637a201 100644
--- a/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/test/gapic_naming_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/naming-esm/esm/test/gapic_naming_v1beta1.ts.baseline
@@ -256,9 +256,7 @@ describe('v1beta1.NamingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -273,9 +271,7 @@ describe('v1beta1.NamingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/naming/test/gapic_naming_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/naming/test/gapic_naming_v1beta1.ts.baseline
index 3a396e5da3a3..2b40467d6508 100644
--- a/core/generator/gapic-generator-typescript/baselines/naming/test/gapic_naming_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/naming/test/gapic_naming_v1beta1.ts.baseline
@@ -245,9 +245,7 @@ describe('v1beta1.NamingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -262,9 +260,7 @@ describe('v1beta1.NamingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline
index 9e85580ce628..6a7561504630 100644
--- a/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/redis-esm/esm/test/gapic_cloud_redis_v1beta1.ts.baseline
@@ -305,9 +305,7 @@ describe('v1beta1.CloudRedisClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -322,9 +320,7 @@ describe('v1beta1.CloudRedisClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline
index bfe18af20135..3dbf530bf99b 100644
--- a/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/redis/test/gapic_cloud_redis_v1beta1.ts.baseline
@@ -294,9 +294,7 @@ describe('v1beta1.CloudRedisClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -311,9 +309,7 @@ describe('v1beta1.CloudRedisClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/resumable-upload-esm/esm/src/v1/resumable_upload_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/resumable-upload-esm/esm/src/v1/resumable_upload_service_client.ts.baseline
index 9e8bb8a26518..daf30c8e7ed9 100644
--- a/core/generator/gapic-generator-typescript/baselines/resumable-upload-esm/esm/src/v1/resumable_upload_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/resumable-upload-esm/esm/src/v1/resumable_upload_service_client.ts.baseline
@@ -621,6 +621,7 @@ export class ResumableUploadServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/resumable-upload-esm/esm/test/gapic_resumable_upload_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/resumable-upload-esm/esm/test/gapic_resumable_upload_service_v1.ts.baseline
index f9fdbf6e2ce8..957148641588 100644
--- a/core/generator/gapic-generator-typescript/baselines/resumable-upload-esm/esm/test/gapic_resumable_upload_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/resumable-upload-esm/esm/test/gapic_resumable_upload_service_v1.ts.baseline
@@ -221,10 +221,9 @@ describe('v1.ResumableUploadServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -238,10 +237,9 @@ describe('v1.ResumableUploadServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/resumable-upload/src/v1/resumable_upload_service_client.ts.baseline b/core/generator/gapic-generator-typescript/baselines/resumable-upload/src/v1/resumable_upload_service_client.ts.baseline
index 5cf29b918896..82ae832846df 100644
--- a/core/generator/gapic-generator-typescript/baselines/resumable-upload/src/v1/resumable_upload_service_client.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/resumable-upload/src/v1/resumable_upload_service_client.ts.baseline
@@ -599,6 +599,7 @@ export class ResumableUploadServiceClient {
         this._log.info('ending gRPC channel');
         this._terminated = true;
         stub.close();
+        return;
       });
     }
     return Promise.resolve();
diff --git a/core/generator/gapic-generator-typescript/baselines/resumable-upload/test/gapic_resumable_upload_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/resumable-upload/test/gapic_resumable_upload_service_v1.ts.baseline
index f8fa88cfa884..74fc6201c238 100644
--- a/core/generator/gapic-generator-typescript/baselines/resumable-upload/test/gapic_resumable_upload_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/resumable-upload/test/gapic_resumable_upload_service_v1.ts.baseline
@@ -210,10 +210,9 @@ describe('v1.ResumableUploadServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -227,10 +226,9 @@ describe('v1.ResumableUploadServiceClient', () => {
         .close()
         .then(() => {
           done();
+          return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_analytics_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_analytics_service_v2alpha.ts.baseline
index a2fd45338e38..d298ea174551 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_analytics_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_analytics_service_v2alpha.ts.baseline
@@ -238,9 +238,7 @@ describe('v2alpha.AnalyticsServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -255,9 +253,7 @@ describe('v2alpha.AnalyticsServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_branch_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_branch_service_v2alpha.ts.baseline
index 1910a3e55980..df5d736c1eb1 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_branch_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_branch_service_v2alpha.ts.baseline
@@ -210,9 +210,7 @@ describe('v2alpha.BranchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -227,9 +225,7 @@ describe('v2alpha.BranchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_catalog_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_catalog_service_v2alpha.ts.baseline
index 83628567c754..7dd5b612ead3 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_catalog_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_catalog_service_v2alpha.ts.baseline
@@ -274,9 +274,7 @@ describe('v2alpha.CatalogServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -291,9 +289,7 @@ describe('v2alpha.CatalogServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_completion_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_completion_service_v2alpha.ts.baseline
index 31af7c27094e..bbb72db650a1 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_completion_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_completion_service_v2alpha.ts.baseline
@@ -252,9 +252,7 @@ describe('v2alpha.CompletionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -270,9 +268,7 @@ describe('v2alpha.CompletionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_control_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_control_service_v2alpha.ts.baseline
index 1268a3016685..c76e24cc144a 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_control_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_control_service_v2alpha.ts.baseline
@@ -274,9 +274,7 @@ describe('v2alpha.ControlServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -291,9 +289,7 @@ describe('v2alpha.ControlServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_conversational_search_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_conversational_search_service_v2alpha.ts.baseline
index c071c8b2c8ea..137adbe87581 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_conversational_search_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_conversational_search_service_v2alpha.ts.baseline
@@ -237,9 +237,7 @@ describe('v2alpha.ConversationalSearchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -257,9 +255,7 @@ describe('v2alpha.ConversationalSearchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_generative_question_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_generative_question_service_v2alpha.ts.baseline
index 61722e63127b..d4ac2eec291b 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_generative_question_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_generative_question_service_v2alpha.ts.baseline
@@ -229,9 +229,7 @@ describe('v2alpha.GenerativeQuestionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -249,9 +247,7 @@ describe('v2alpha.GenerativeQuestionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
index fbe5de8fe6e0..abf8d6986988 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
@@ -264,9 +264,7 @@ describe('v2alpha.MerchantCenterAccountLinkServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -287,9 +285,7 @@ describe('v2alpha.MerchantCenterAccountLinkServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_model_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_model_service_v2alpha.ts.baseline
index 1c5f191d298b..c7cf2c926348 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_model_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_model_service_v2alpha.ts.baseline
@@ -305,9 +305,7 @@ describe('v2alpha.ModelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -322,9 +320,7 @@ describe('v2alpha.ModelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_prediction_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_prediction_service_v2alpha.ts.baseline
index 01b2a79e26f0..9b9665ce8b2a 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_prediction_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_prediction_service_v2alpha.ts.baseline
@@ -220,9 +220,7 @@ describe('v2alpha.PredictionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -238,9 +236,7 @@ describe('v2alpha.PredictionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_product_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_product_service_v2alpha.ts.baseline
index c2ab22595e38..86af75e3c420 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_product_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_product_service_v2alpha.ts.baseline
@@ -306,9 +306,7 @@ describe('v2alpha.ProductServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -323,9 +321,7 @@ describe('v2alpha.ProductServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_project_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_project_service_v2alpha.ts.baseline
index ffa539fe5e9c..0ce39d22ab31 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_project_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_project_service_v2alpha.ts.baseline
@@ -243,9 +243,7 @@ describe('v2alpha.ProjectServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -260,9 +258,7 @@ describe('v2alpha.ProjectServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_search_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_search_service_v2alpha.ts.baseline
index 9cd1a26ba602..709e9da00d0a 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_search_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_search_service_v2alpha.ts.baseline
@@ -273,9 +273,7 @@ describe('v2alpha.SearchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -290,9 +288,7 @@ describe('v2alpha.SearchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_serving_config_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_serving_config_service_v2alpha.ts.baseline
index 9927d5ab72ed..27015a17b293 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_serving_config_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_serving_config_service_v2alpha.ts.baseline
@@ -286,9 +286,7 @@ describe('v2alpha.ServingConfigServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -304,9 +302,7 @@ describe('v2alpha.ServingConfigServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_user_event_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_user_event_service_v2alpha.ts.baseline
index b50bea4bf0ef..7ce3b302b65d 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_user_event_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail-esm/esm/test/gapic_user_event_service_v2alpha.ts.baseline
@@ -247,9 +247,7 @@ describe('v2alpha.UserEventServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -264,9 +262,7 @@ describe('v2alpha.UserEventServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_analytics_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_analytics_service_v2alpha.ts.baseline
index 5cfe52e9002d..81d1c1f0c1c1 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_analytics_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_analytics_service_v2alpha.ts.baseline
@@ -227,9 +227,7 @@ describe('v2alpha.AnalyticsServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -244,9 +242,7 @@ describe('v2alpha.AnalyticsServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_branch_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_branch_service_v2alpha.ts.baseline
index 40a22dd4ac7a..63c17111a59b 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_branch_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_branch_service_v2alpha.ts.baseline
@@ -199,9 +199,7 @@ describe('v2alpha.BranchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -216,9 +214,7 @@ describe('v2alpha.BranchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_catalog_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_catalog_service_v2alpha.ts.baseline
index b418212c6b69..40162482de62 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_catalog_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_catalog_service_v2alpha.ts.baseline
@@ -263,9 +263,7 @@ describe('v2alpha.CatalogServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -280,9 +278,7 @@ describe('v2alpha.CatalogServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_completion_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_completion_service_v2alpha.ts.baseline
index 5bbf2721dcb1..df3cda656636 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_completion_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_completion_service_v2alpha.ts.baseline
@@ -241,9 +241,7 @@ describe('v2alpha.CompletionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -259,9 +257,7 @@ describe('v2alpha.CompletionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_control_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_control_service_v2alpha.ts.baseline
index fdb3bcee12bc..c1e42f019dae 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_control_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_control_service_v2alpha.ts.baseline
@@ -263,9 +263,7 @@ describe('v2alpha.ControlServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -280,9 +278,7 @@ describe('v2alpha.ControlServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_conversational_search_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_conversational_search_service_v2alpha.ts.baseline
index 7120acc5d119..e80ca770d3d4 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_conversational_search_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_conversational_search_service_v2alpha.ts.baseline
@@ -226,9 +226,7 @@ describe('v2alpha.ConversationalSearchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -246,9 +244,7 @@ describe('v2alpha.ConversationalSearchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_generative_question_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_generative_question_service_v2alpha.ts.baseline
index 77fb854cd818..d8da8f6a7b6e 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_generative_question_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_generative_question_service_v2alpha.ts.baseline
@@ -218,9 +218,7 @@ describe('v2alpha.GenerativeQuestionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -238,9 +236,7 @@ describe('v2alpha.GenerativeQuestionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
index d1bedf1f3550..d61a81652c47 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_merchant_center_account_link_service_v2alpha.ts.baseline
@@ -253,9 +253,7 @@ describe('v2alpha.MerchantCenterAccountLinkServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -276,9 +274,7 @@ describe('v2alpha.MerchantCenterAccountLinkServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_model_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_model_service_v2alpha.ts.baseline
index 403dc23c596f..0690d34656d2 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_model_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_model_service_v2alpha.ts.baseline
@@ -294,9 +294,7 @@ describe('v2alpha.ModelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -311,9 +309,7 @@ describe('v2alpha.ModelServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_prediction_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_prediction_service_v2alpha.ts.baseline
index 6668326f938e..38852d078962 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_prediction_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_prediction_service_v2alpha.ts.baseline
@@ -209,9 +209,7 @@ describe('v2alpha.PredictionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -227,9 +225,7 @@ describe('v2alpha.PredictionServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_product_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_product_service_v2alpha.ts.baseline
index 1a2a1df9ebc4..c73b81719b84 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_product_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_product_service_v2alpha.ts.baseline
@@ -295,9 +295,7 @@ describe('v2alpha.ProductServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -312,9 +310,7 @@ describe('v2alpha.ProductServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_project_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_project_service_v2alpha.ts.baseline
index d10d243c2f6e..95004a6785d9 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_project_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_project_service_v2alpha.ts.baseline
@@ -232,9 +232,7 @@ describe('v2alpha.ProjectServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -249,9 +247,7 @@ describe('v2alpha.ProjectServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_search_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_search_service_v2alpha.ts.baseline
index 6a5c6bca776e..1fe2a7e3d7d4 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_search_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_search_service_v2alpha.ts.baseline
@@ -262,9 +262,7 @@ describe('v2alpha.SearchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -279,9 +277,7 @@ describe('v2alpha.SearchServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_serving_config_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_serving_config_service_v2alpha.ts.baseline
index 516da0ffe48b..9a90d1f478bb 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_serving_config_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_serving_config_service_v2alpha.ts.baseline
@@ -275,9 +275,7 @@ describe('v2alpha.ServingConfigServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -293,9 +291,7 @@ describe('v2alpha.ServingConfigServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_user_event_service_v2alpha.ts.baseline b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_user_event_service_v2alpha.ts.baseline
index 9cc85191b8c8..b98bfbebae46 100644
--- a/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_user_event_service_v2alpha.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/retail/test/gapic_user_event_service_v2alpha.ts.baseline
@@ -236,9 +236,7 @@ describe('v2alpha.UserEventServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -253,9 +251,7 @@ describe('v2alpha.UserEventServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/test/gapic_test_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/test/gapic_test_service_v1.ts.baseline
index ab4202aad645..7a90b3d15c46 100644
--- a/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/test/gapic_test_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/routingtest-esm/esm/test/gapic_test_service_v1.ts.baseline
@@ -161,9 +161,7 @@ describe('v1.TestServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -178,9 +176,7 @@ describe('v1.TestServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/routingtest/test/gapic_test_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/routingtest/test/gapic_test_service_v1.ts.baseline
index 2cfa2bc540f6..7d9b95c15408 100644
--- a/core/generator/gapic-generator-typescript/baselines/routingtest/test/gapic_test_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/routingtest/test/gapic_test_service_v1.ts.baseline
@@ -150,9 +150,7 @@ describe('v1.TestServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -167,9 +165,7 @@ describe('v1.TestServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_compliance_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
index 20a3891b7d93..a2199efabb11 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_compliance_v1beta1.ts.baseline
@@ -163,9 +163,7 @@ describe('v1beta1.ComplianceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -180,9 +178,7 @@ describe('v1beta1.ComplianceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_echo_v1beta1.ts.baseline
index 6225a291baf1..7069ae18ce14 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_echo_v1beta1.ts.baseline
@@ -306,9 +306,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -323,9 +321,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_identity_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_identity_v1beta1.ts.baseline
index 1cb9cb307920..5e58be660335 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_identity_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_identity_v1beta1.ts.baseline
@@ -224,9 +224,7 @@ describe('v1beta1.IdentityClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -241,9 +239,7 @@ describe('v1beta1.IdentityClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_messaging_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
index ffd4fdf763e8..a7cfa94622fb 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_messaging_v1beta1.ts.baseline
@@ -306,9 +306,7 @@ describe('v1beta1.MessagingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -323,9 +321,7 @@ describe('v1beta1.MessagingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
index b9e4f3e9097c..822e8c312493 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_sequence_service_v1beta1.ts.baseline
@@ -163,9 +163,7 @@ describe('v1beta1.SequenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -180,9 +178,7 @@ describe('v1beta1.SequenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_testing_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_testing_v1beta1.ts.baseline
index 14b0f953fd35..77efcb0e588c 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_testing_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-esm/esm/test/gapic_testing_v1beta1.ts.baseline
@@ -224,9 +224,7 @@ describe('v1beta1.TestingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -241,9 +239,7 @@ describe('v1beta1.TestingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/test/gapic_echo_v1beta1.ts.baseline
index 08d980cda4b8..1378efac5c7d 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-legacy-esm/esm/test/gapic_echo_v1beta1.ts.baseline
@@ -281,9 +281,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -298,9 +296,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase-legacy/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase-legacy/test/gapic_echo_v1beta1.ts.baseline
index 35d262ccb66c..4aebc167ae78 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase-legacy/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase-legacy/test/gapic_echo_v1beta1.ts.baseline
@@ -280,9 +280,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -297,9 +295,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_compliance_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_compliance_v1beta1.ts.baseline
index 2ee428d6bdb7..6bdf50e04168 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_compliance_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_compliance_v1beta1.ts.baseline
@@ -152,9 +152,7 @@ describe('v1beta1.ComplianceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -169,9 +167,7 @@ describe('v1beta1.ComplianceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_echo_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_echo_v1beta1.ts.baseline
index cf181d5f25a9..300728362ef8 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_echo_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_echo_v1beta1.ts.baseline
@@ -295,9 +295,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -312,9 +310,7 @@ describe('v1beta1.EchoClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_identity_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_identity_v1beta1.ts.baseline
index f32f7f9210b5..a8257690745a 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_identity_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_identity_v1beta1.ts.baseline
@@ -213,9 +213,7 @@ describe('v1beta1.IdentityClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -230,9 +228,7 @@ describe('v1beta1.IdentityClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_messaging_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_messaging_v1beta1.ts.baseline
index 6bf50c4a7ece..187ad4e277a3 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_messaging_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_messaging_v1beta1.ts.baseline
@@ -295,9 +295,7 @@ describe('v1beta1.MessagingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -312,9 +310,7 @@ describe('v1beta1.MessagingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_sequence_service_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_sequence_service_v1beta1.ts.baseline
index 8fed411f2e64..f4256cba7d3a 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_sequence_service_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_sequence_service_v1beta1.ts.baseline
@@ -152,9 +152,7 @@ describe('v1beta1.SequenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -169,9 +167,7 @@ describe('v1beta1.SequenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_testing_v1beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_testing_v1beta1.ts.baseline
index 75f225c4b150..b7ae75c8ec5a 100644
--- a/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_testing_v1beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/showcase/test/gapic_testing_v1beta1.ts.baseline
@@ -213,9 +213,7 @@ describe('v1beta1.TestingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -230,9 +228,7 @@ describe('v1beta1.TestingClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/test/gapic_cloud_tasks_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/test/gapic_cloud_tasks_v2.ts.baseline
index a75a1198747b..d3ae8f4cef03 100644
--- a/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/test/gapic_cloud_tasks_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/tasks-esm/esm/test/gapic_cloud_tasks_v2.ts.baseline
@@ -271,9 +271,7 @@ describe('v2.CloudTasksClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -288,9 +286,7 @@ describe('v2.CloudTasksClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/tasks/test/gapic_cloud_tasks_v2.ts.baseline b/core/generator/gapic-generator-typescript/baselines/tasks/test/gapic_cloud_tasks_v2.ts.baseline
index e9559144ed91..40c9c7c98982 100644
--- a/core/generator/gapic-generator-typescript/baselines/tasks/test/gapic_cloud_tasks_v2.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/tasks/test/gapic_cloud_tasks_v2.ts.baseline
@@ -260,9 +260,7 @@ describe('v2.CloudTasksClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -277,9 +275,7 @@ describe('v2.CloudTasksClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/test/gapic_text_to_speech_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/test/gapic_text_to_speech_v1.ts.baseline
index 03d6183f7d11..7d5309215feb 100644
--- a/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/test/gapic_text_to_speech_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/texttospeech-esm/esm/test/gapic_text_to_speech_v1.ts.baseline
@@ -213,9 +213,7 @@ describe('v1.TextToSpeechClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -230,9 +228,7 @@ describe('v1.TextToSpeechClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/texttospeech/test/gapic_text_to_speech_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/texttospeech/test/gapic_text_to_speech_v1.ts.baseline
index 9664d29025c7..e02242ce9b33 100644
--- a/core/generator/gapic-generator-typescript/baselines/texttospeech/test/gapic_text_to_speech_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/texttospeech/test/gapic_text_to_speech_v1.ts.baseline
@@ -202,9 +202,7 @@ describe('v1.TextToSpeechClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -219,9 +217,7 @@ describe('v1.TextToSpeechClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/test/gapic_translation_service_v3beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/test/gapic_translation_service_v3beta1.ts.baseline
index 953f4a83e4ff..f26e77c58e4a 100644
--- a/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/test/gapic_translation_service_v3beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/translate-esm/esm/test/gapic_translation_service_v3beta1.ts.baseline
@@ -316,9 +316,7 @@ describe('v3beta1.TranslationServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -334,9 +332,7 @@ describe('v3beta1.TranslationServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/translate/test/gapic_translation_service_v3beta1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/translate/test/gapic_translation_service_v3beta1.ts.baseline
index f5a7478c6740..d91de4f6117a 100644
--- a/core/generator/gapic-generator-typescript/baselines/translate/test/gapic_translation_service_v3beta1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/translate/test/gapic_translation_service_v3beta1.ts.baseline
@@ -305,9 +305,7 @@ describe('v3beta1.TranslationServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -323,9 +321,7 @@ describe('v3beta1.TranslationServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/test/gapic_video_intelligence_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/test/gapic_video_intelligence_service_v1.ts.baseline
index cfefcfd51e8d..94c839eecd41 100644
--- a/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/test/gapic_video_intelligence_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/videointelligence-esm/esm/test/gapic_video_intelligence_service_v1.ts.baseline
@@ -249,9 +249,7 @@ describe('v1.VideoIntelligenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -267,9 +265,7 @@ describe('v1.VideoIntelligenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/baselines/videointelligence/test/gapic_video_intelligence_service_v1.ts.baseline b/core/generator/gapic-generator-typescript/baselines/videointelligence/test/gapic_video_intelligence_service_v1.ts.baseline
index 886a5d348e35..87abf4181a26 100644
--- a/core/generator/gapic-generator-typescript/baselines/videointelligence/test/gapic_video_intelligence_service_v1.ts.baseline
+++ b/core/generator/gapic-generator-typescript/baselines/videointelligence/test/gapic_video_intelligence_service_v1.ts.baseline
@@ -238,9 +238,7 @@ describe('v1.VideoIntelligenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has close method for the non-initialized client', done => {
@@ -256,9 +254,7 @@ describe('v1.VideoIntelligenceServiceClient', () => {
           done();
           return;
         })
-        .catch(err => {
-          throw err;
-        });
+        .catch(done);
     });
 
     it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk b/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk
index 5e83e829585e..fa34ca958483 100644
--- a/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk
+++ b/core/generator/gapic-generator-typescript/templates/cjs/typescript_gapic/test/gapic_$service_$version.ts.njk
@@ -327,7 +327,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
             client.{{ id.get("close") }}().then(() => {
                 done();
                 return;
-            }).catch(err => {throw err});
+            }).catch(done);
         });
 
         it('has close method for the non-initialized client', done => {
@@ -336,7 +336,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
             client.{{ id.get("close") }}().then(() => {
                 done();
                 return;
-            }).catch(err => {throw err});
+            }).catch(done);
         });
 
         it('has getProjectId method', async () => {
diff --git a/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk b/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk
index 8908e79cac25..7cecd2e312f3 100644
--- a/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk
+++ b/core/generator/gapic-generator-typescript/templates/esm/typescript_gapic/esm/test/gapic_$service_$version.ts.njk
@@ -334,7 +334,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
             client.{{ id.get("close") }}().then(() => {
                 done();
                 return;
-            }).catch(err => {throw err});
+            }).catch(done);
         });
 
         it('has close method for the non-initialized client', done => {
@@ -343,7 +343,7 @@ describe('{{ api.naming.version }}.{{ service.name }}Client', () => {
             client.{{ id.get("close") }}().then(() => {
                 done();
                 return;
-            }).catch(err => {throw err});
+            }).catch(done);
         });
 
         it('has getProjectId method', async () => {