ci: add nightly contract tests with long-running tests enabled

.github/actions/contract-tests/action.yml

@@ -15,6 +15,10 @@ inputs:
     description: 'Whether to run contract tests from the latest v3 release'
     required: false
     default: 'false'
+  enable_long_running_tests:
+    description: 'Whether to run harness tests that wait on real backoff timing. These add about an hour, so only the nightly enables them.'
+    required: false
+    default: 'false'
 
 runs:
   using: composite
@@ -54,7 +58,7 @@ runs:
         enable_persistence_tests: 'false'
         # Leave the service up for the FDv2 run that follows.
         stop_service: ${{ inputs.run_fdv2_tests == 'true' && 'false' || 'true' }}
-        extra_params: '-status-timeout=360 -skip-from=${{ env.SUPPRESSION_FILE }}'
+        extra_params: "-status-timeout=360 -skip-from=${{ env.SUPPRESSION_FILE }}${{ inputs.enable_long_running_tests == 'true' && ' -enable-long-running-tests' || '' }}"
         token: ${{ inputs.token }}
 
     - name: Run Contract Tests FDv2 Flavor
@@ -65,7 +69,7 @@ runs:
         version: 'v3'
         debug_logging: 'true'
         enable_persistence_tests: 'false'
-        extra_params: '-status-timeout=360 -skip-from=${{ env.SUPPRESSION_FILE_FDV2 }}'
+        extra_params: "-status-timeout=360 -skip-from=${{ env.SUPPRESSION_FILE_FDV2 }}${{ inputs.enable_long_running_tests == 'true' && ' -enable-long-running-tests' || '' }}"
         token: ${{ inputs.token }}
 
     - name: Upload test service log on failure

.github/workflows/sdk-server-nightly.yml

@@ -0,0 +1,48 @@
+name: LaunchDarkly.ServerSdk Nightly Contract Tests
+
+on:
+  schedule:
+    - cron: '0 4 * * *' # every day at 4am UTC
+  workflow_dispatch:
+    inputs:
+      branch:
+        description: 'Branch to run contract tests on'
+        required: false
+        default: ''
+
+permissions:
+  contents: read
+
+jobs:
+  nightly-contract-tests:
+    runs-on: ubuntu-latest
+    # The long-running tests are almost entirely wall-clock waiting, so this job runs
+    # roughly an hour. A regression that stops retrying makes each scenario burn its
+    # full timeout instead of returning early, so leave headroom -- while staying well
+    # under the 6-hour default that would otherwise apply.
+    timeout-minutes: 120
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.branch || github.ref }}
+
+      - name: Setup Env from project's Env file
+        shell: bash
+        run: cat pkgs/sdk/server/github_actions.env >> "$GITHUB_ENV"
+
+      - uses: ./.github/actions/contract-tests
+        with:
+          service_project_file: ${{ env.CONTRACT_TEST_PROJECT_FILE }}
+          service_dll_file: ${{ env.CONTRACT_TEST_DLL_FILE }}
+          token: ${{ secrets.GITHUB_TOKEN }}
+          run_fdv2_tests: 'true'
+          enable_long_running_tests: 'true'
+
+      - name: Upload test service log
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: contract-test-service-log
+          path: test-service.log
+          if-no-files-found: warn