fix: reopen root container on startup across broker restarts

modern_di_faststream/main.py

@@ -68,6 +68,11 @@ def setup_di(
 
     container.providers_registry.add_providers(faststream_message_provider)
     app.context.set_global("di_container", container)
+    # FastStream's lifecycle is callback-based, so the root container can't be
+    # wrapped in ``async with``. Reopen it on startup (before the broker consumes)
+    # to pair with the shutdown close, so a broker restart works instead of
+    # raising ContainerClosedError. Reopening an already-open container is a no-op.
+    app.on_startup(container.open)
     app.after_shutdown(container.close_async)
     # _DIMiddlewareFactory.__call__ ParamSpec doesn't structurally match BrokerMiddleware[Any, Any].
     app.broker.add_middleware(_DIMiddlewareFactory(container))  # ty: ignore[invalid-argument-type]

pyproject.toml

@@ -15,7 +15,7 @@ classifiers = [
     "Typing :: Typed",
     "Topic :: Software Development :: Libraries",
 ]
-dependencies = ["faststream>=0.7,<0.8", "modern-di>=2.16.1,<3"]
+dependencies = ["faststream>=0.7,<0.8", "modern-di>=2.19.0,<3"]
 version = "0"
 
 [project.urls]

tests/test_lifespan.py

@@ -0,0 +1,36 @@
+import typing
+
+import faststream
+from faststream import TestApp
+from faststream.nats import NatsBroker, TestNatsBroker
+
+from modern_di_faststream import FromDI, fetch_di_container
+from tests.dependencies import Dependencies, SimpleCreator
+
+
+TEST_SUBJECT = "test"
+
+
+async def test_startup_reopens_container_across_cycles(app: faststream.FastStream) -> None:
+    broker = typing.cast(NatsBroker, app.broker)
+    container = fetch_di_container(app)
+
+    @broker.subscriber(TEST_SUBJECT)
+    async def index_subscriber(
+        message: str,
+        instance: typing.Annotated[SimpleCreator, FromDI(Dependencies.app_factory)],
+    ) -> None:
+        assert message == "test"
+        assert isinstance(instance, SimpleCreator)
+
+    async with TestNatsBroker(broker) as br:
+        # First lifecycle: after_shutdown closes the root container.
+        async with TestApp(app):
+            await br.publish("test", TEST_SUBJECT)
+        assert container.closed
+
+        # Second lifecycle: on_startup must reopen the same container, so the
+        # middleware can build a request child instead of raising ContainerClosedError.
+        async with TestApp(app):
+            assert not container.closed
+            await br.publish("test", TEST_SUBJECT)