fix: namespace the context keys and read the request container as a local

modern_di_faststream/main.py

@@ -16,8 +16,8 @@
 # Keys under which the containers live in FastStream's ``ContextRepo``. Each is
 # written in one place and read in another; naming them keeps writer and reader
 # in provable agreement instead of relying on two matching string literals.
-_ROOT_CONTAINER_KEY = "di_container"
-_REQUEST_CONTAINER_KEY = "request_container"
+_ROOT_CONTAINER_KEY = "modern_di_root_container"
+_REQUEST_CONTAINER_KEY = "modern_di_request_container"
 
 _MISSING_REQUEST_CONTAINER = (
     "No request container for this message, so the DI middleware did not run for it. "
@@ -99,7 +99,7 @@ class Dependency(typing.Generic[T_co]):
     marker: integrations.Marker[T_co]
 
     async def __call__(self, context: faststream.ContextRepo) -> T_co:
-        request_container: Container | None = context.get(_REQUEST_CONTAINER_KEY)
+        request_container: Container | None = context.get_local(_REQUEST_CONTAINER_KEY)
         if request_container is None:
             raise RuntimeError(_MISSING_REQUEST_CONTAINER)
         return self.marker.resolve(request_container)

tests/test_faststream_di.py

@@ -87,6 +87,28 @@ def test_fetch_di_container(app: faststream.FastStream) -> None:
     assert isinstance(di_container, Container)
 
 
+def test_fetch_di_container_ignores_a_user_global_named_di_container() -> None:
+    app_ = faststream.FastStream(NatsBroker())
+    container = modern_di_faststream.setup_di(app_, container=Container(groups=[Dependencies]))
+    app_.context.set_global("di_container", "user value")
+
+    assert modern_di_faststream.fetch_di_container(app_) is container
+
+
+async def test_from_di_ignores_a_user_global_named_request_container() -> None:
+    broker = NatsBroker()
+    app_ = faststream.FastStream(broker)
+    modern_di_faststream.setup_di(app_, container=Container(groups=[Dependencies]))
+    broker.context.set_global("request_container", "user value")
+    resolved: list[SimpleCreator] = []
+    _subscribe_resolving(broker, TEST_SUBJECT, resolved)
+
+    async with TestNatsBroker(broker) as br, TestApp(app_):
+        await br.publish(None, TEST_SUBJECT)
+
+    assert [type(instance) for instance in resolved] == [SimpleCreator]
+
+
 def _app_with_two_brokers(*, add_second_after_setup: bool) -> tuple[faststream.FastStream, NatsBroker, NatsBroker]:
     first, second = NatsBroker(), NatsBroker()
     app_ = faststream.FastStream(first) if add_second_after_setup else faststream.FastStream(first, second)
@@ -151,7 +173,7 @@ async def subscriber(instance: typing.Annotated[SimpleCreator, FromDI(Dependenci
 async def test_from_di_without_setup_di_names_the_missing_step() -> None:
     """INVARIANT: ``FromDI`` on a message the DI middleware never saw fails by naming ``setup_di``.
 
-    Broken by handing ``ContextRepo.get``'s ``None`` straight to the marker, which surfaces as
+    Broken by handing ``ContextRepo.get_local``'s ``None`` straight to the marker, which surfaces as
     modern-di's ``AttributeError: 'NoneType' object has no attribute 'resolve_dependency'`` and
     points at nothing in this package.
     """