fix: remove FastStream's stderr handler while lite-bootstrap logs FastStream records

lite_bootstrap/bootstrappers/faststream_bootstrapper.py

@@ -151,11 +151,17 @@ class FastStreamLoggingInstrument(LoggingInstrument[FastStreamConfig]):
     _prior_broker_params_storages: list[tuple[typing.Any, typing.Any]] = dataclasses.field(
         default_factory=list, init=False, repr=False, compare=False
     )
+    _prior_faststream_handlers: list[logging.Handler] | None = dataclasses.field(
+        default=None, init=False, repr=False, compare=False
+    )
 
     def bootstrap(self) -> None:
         super().bootstrap()
         brokers = self.bootstrap_config.application.brokers
         if brokers and import_checker.is_structlog_installed and import_checker.is_faststream_installed:
+            faststream_stdlib_logger = logging.getLogger("faststream")
+            self._prior_faststream_handlers = faststream_stdlib_logger.handlers
+            faststream_stdlib_logger.handlers = []
             logger = structlog.get_logger("faststream")
             logger.setLevel(self.bootstrap_config.faststream_log_level)
             for broker in brokers:
@@ -168,7 +174,12 @@ def teardown(self) -> None:
                 broker, prior_storage = self._prior_broker_params_storages.pop()
                 broker.config.logger.params_storage = prior_storage
         finally:
-            super().teardown()
+            try:
+                super().teardown()
+            finally:
+                if self._prior_faststream_handlers is not None:
+                    logging.getLogger("faststream").handlers = self._prior_faststream_handlers
+                    self._prior_faststream_handlers = None
 
 
 @dataclasses.dataclass(kw_only=True)

tests/test_faststream_bootstrap.py

@@ -1,5 +1,7 @@
 import dataclasses
 import logging
+import logging.handlers
+import sys
 import typing
 import uuid
 import warnings
@@ -152,6 +154,26 @@ def test_faststream_logging_instrument_injects_structlog_logger(broker: RedisBro
         bootstrapper.teardown()
 
 
+def test_faststream_logging_replaces_faststream_stderr_handler(broker: RedisBroker) -> None:
+    faststream_logger = logging.getLogger("faststream")
+    original_handlers = faststream_logger.handlers[:]
+    bootstrapper = FastStreamBootstrapper(
+        bootstrap_config=FastStreamConfig(
+            logging_buffer_capacity=0,
+            faststream_log_level=logging.INFO,
+            application=faststream.asgi.AsgiFastStream(broker),
+        )
+    )
+    bootstrapper.bootstrap()
+    try:
+        assert not [one for one in faststream_logger.handlers if getattr(one, "stream", None) is sys.stderr]
+        assert [type(one) for one in faststream_logger.handlers].count(logging.handlers.MemoryHandler) == 1
+    finally:
+        bootstrapper.teardown()
+
+    assert faststream_logger.handlers == original_handlers
+
+
 def test_faststream_config_default_application() -> None:
     config = FastStreamConfig()
     assert isinstance(config.application, faststream.asgi.AsgiFastStream)