test: FastDependsConfig merging

Author: nectarindev

tests/application/test_delayed_broker.py

@@ -1,6 +1,8 @@
 import pytest
 
 from faststream._internal.application import StartAbleApplication
+from faststream._internal.context import ContextRepo
+from faststream._internal.di import FastDependsConfig
 from faststream.exceptions import SetupError
 from faststream.rabbit import RabbitBroker
 
@@ -45,3 +47,32 @@ async def test_di_reconfigured() -> None:
     app.set_broker(broker)
 
     assert broker.context.get("app") is app
+
+
+def test_broker_and_app_contexts_merge() -> None:
+    broker = RabbitBroker(
+        context=ContextRepo({
+            "broker_dependency": 1,
+            "override_dependency": 2,
+        })
+    )
+
+    config = FastDependsConfig(
+        context=ContextRepo({
+            "application_dependency": 3,
+            "override_dependency": 4,
+        })
+    )
+    app = StartAbleApplication(config=config)
+    application_context = app.context
+
+    # if the broker binds to the application,
+    # the broker modifies the application context and uses it as its own.
+    app.set_broker(broker)
+
+    assert app.context is application_context
+    assert broker.context is application_context
+    assert app.context.get("broker_dependency") == 1
+    assert app.context.get("application_dependency") == 3
+    # the broker context overwrites the application context
+    assert app.context.get("override_dependency") == 2