From c0c297b258a2ab9c9ebac8b8a9f87fe7ebf10ffc Mon Sep 17 00:00:00 2001
From: Artur Shiriev <lesnik512@gmail.com>
Date: Tue, 3 Nov 2026 11:26:59 +0300
Subject: [PATCH] Serve both FastStream probe path spellings

Closes #397
---
 docs/integrations/faststream.md               |  7 +++++
 .../bootstrappers/faststream_bootstrapper.py  | 20 +++++++++---
 tests/test_faststream_bootstrap.py            | 31 +++++++++++++++++++
 3 files changed, 54 insertions(+), 4 deletions(-)

diff --git a/docs/integrations/faststream.md b/docs/integrations/faststream.md
index e6ef526..bdb35bc 100644
--- a/docs/integrations/faststream.md
+++ b/docs/integrations/faststream.md
@@ -51,6 +51,13 @@ application = bootstrapper.bootstrap()
 
 Read more about available configuration options [here](../introduction/configuration.md).
 
+## Health and metrics routes
+
+When configured, FastStream health and Prometheus metrics routes accept requests with or without
+the trailing slash. For example, both `/health` and `/health/` reach the same health check, and a
+metrics path configured as `/metrics` also serves `/metrics/`. If the two configured paths differ only by a trailing slash, each
+route keeps its explicitly configured path.
+
 ## Multiple brokers
 
 Tracing, metrics and logging cover every broker the application has when `bootstrap()` runs. Add
diff --git a/lite_bootstrap/bootstrappers/faststream_bootstrapper.py b/lite_bootstrap/bootstrappers/faststream_bootstrapper.py
index 18323e2..cb8dc40 100644
--- a/lite_bootstrap/bootstrappers/faststream_bootstrapper.py
+++ b/lite_bootstrap/bootstrappers/faststream_bootstrapper.py
@@ -114,6 +114,11 @@ def _middleware_targets(
     return targets
 
 
+def _route_path_variants(path: str) -> tuple[str, ...]:
+    alternate_path = path.removesuffix("/") if path.endswith("/") else f"{path}/"
+    return (path, alternate_path) if alternate_path else (path,)
+
+
 def _make_asgi_faststream() -> "AsgiFastStream":
     return AsgiFastStream()
 
@@ -154,7 +159,14 @@ async def check_health(_: object) -> "AsgiResponse":
         if config.opentelemetry_generate_health_check_spans and import_checker.is_opentelemetry_installed:
             check_health = tracer.start_as_current_span(f"GET {config.health_checks_path}")(check_health)
 
-        config.application.mount(config.health_checks_path, check_health)
+        for path in _route_path_variants(config.health_checks_path):
+            if (
+                path != config.health_checks_path
+                and path == config.prometheus_metrics_path
+                and FastStreamPrometheusInstrument.dependencies_installed()
+            ):
+                continue
+            config.application.mount(path, check_health)
 
     async def _define_framework_health_status(self) -> bool:
         config = self.bootstrap_config
@@ -236,9 +248,9 @@ def dependencies_installed() -> bool:
 
     def bootstrap(self) -> None:
         config = self.bootstrap_config
-        config.application.mount(
-            config.prometheus_metrics_path, prometheus_client.make_asgi_app(self.collector_registry)
-        )
+        metrics_app = prometheus_client.make_asgi_app(self.collector_registry)
+        for path in _route_path_variants(config.prometheus_metrics_path):
+            config.application.mount(path, metrics_app)
         if config.prometheus_middleware_cls and config.application.brokers:
             for broker, middleware_cls in _middleware_targets(
                 config.application.brokers, config.prometheus_middleware_cls, "prometheus_middleware_cls"
diff --git a/tests/test_faststream_bootstrap.py b/tests/test_faststream_bootstrap.py
index 92b52de..e5b89cd 100644
--- a/tests/test_faststream_bootstrap.py
+++ b/tests/test_faststream_bootstrap.py
@@ -127,6 +127,37 @@ async def test_faststream_bootstrap(broker: RedisBroker) -> None:
     assert not bootstrapper.is_bootstrapped
 
 
+@pytest.mark.parametrize("path", ["/health", "/health/", "/metrics", "/metrics/"])
+async def test_faststream_route_paths_accept_both_slash_forms(broker: RedisBroker, path: str) -> None:
+    config = dataclasses.replace(
+        build_faststream_config(broker=broker), health_checks_path="/health/", prometheus_metrics_path="/metrics"
+    )
+    application = FastStreamBootstrapper(bootstrap_config=config).bootstrap()
+
+    with TestClient(app=application) as test_client:
+        async with TestRedisBroker(broker):
+            response = test_client.get(path, follow_redirects=False)
+
+    assert response.status_code == status.HTTP_200_OK
+
+
+async def test_faststream_configured_metrics_path_takes_precedence_over_health_alias(broker: RedisBroker) -> None:
+    config = dataclasses.replace(
+        build_faststream_config(broker=broker), health_checks_path="/health/", prometheus_metrics_path="/health"
+    )
+    application = FastStreamBootstrapper(bootstrap_config=config).bootstrap()
+
+    with TestClient(app=application) as test_client:
+        async with TestRedisBroker(broker):
+            response = test_client.get("/health")
+            health_response = test_client.get("/health/")
+
+    assert health_response.status_code == status.HTTP_200_OK
+    assert health_response.json()["health_status"] is True
+    assert response.status_code == status.HTTP_200_OK
+    assert response.headers["content-type"].startswith("text/plain")
+
+
 async def test_faststream_sentry_context_is_isolated_per_message(broker: RedisBroker) -> None:
     transport = SentryTestTransport()
     config = FastStreamConfig(