Allow factory kwargs

tests/test_config.py

@@ -49,6 +49,14 @@ def wsgi_app(environ: Environ, start_response: StartResponse) -> None:
     pass  # pragma: nocover
 
 
+def asgi_app_factory(**kwargs):
+    async def app(scope: Scope, receive: ASGIReceiveCallable, send: ASGISendCallable) -> None:
+        pass  # pragma: nocover
+
+    app.factory_kwargs = kwargs  # type: ignore
+    return app
+
+
 @pytest.mark.parametrize(
     "app, expected_should_reload",
     [(asgi_app, False), ("tests.test_config:asgi_app", True)],
@@ -542,6 +550,19 @@ def test_warn_when_using_reload_and_workers(caplog: pytest.LogCaptureFixture) ->
     assert '"workers" flag is ignored when reloading is enabled.' in caplog.records[0].message
 
 
+def test_config_factory_kwargs():
+    config = Config(
+        app="tests.test_config:asgi_app_factory",
+        factory_kwargs={"alpha": 12, "beta": [3, 4, 5]},
+        factory=True,
+        workers=4,
+        proxy_headers=False,
+    )
+    config.load()
+
+    assert config.loaded_app.factory_kwargs == {"alpha": 12, "beta": [3, 4, 5]}
+
+
 @pytest.mark.parametrize(
     ("loop_type", "expected_loop_factory"),
     [

uvicorn/config.py

@@ -225,6 +225,7 @@ def __init__(
         headers: list[tuple[str, str]] | None = None,
         factory: bool = False,
         h11_max_incomplete_event_size: int | None = None,
+        factory_kwargs: dict[str, Any] | None = None,
     ):
         self.app = app
         self.host = host
@@ -270,6 +271,7 @@ def __init__(
         self.encoded_headers: list[tuple[bytes, bytes]] = []
         self.factory = factory
         self.h11_max_incomplete_event_size = h11_max_incomplete_event_size
+        self.factory_kwargs = factory_kwargs or {}
 
         self.loaded = False
         self.configure_logging()
@@ -439,7 +441,7 @@ def load(self) -> None:
             sys.exit(1)
 
         try:
-            self.loaded_app = self.loaded_app()
+            self.loaded_app = self.loaded_app(**self.factory_kwargs)
         except TypeError as exc:
             if self.factory:
                 logger.error("Error loading ASGI app factory: %s", exc)

uvicorn/main.py

@@ -512,6 +512,7 @@ def run(
     app_dir: str | None = None,
     factory: bool = False,
     h11_max_incomplete_event_size: int | None = None,
+    factory_kwargs: dict[str, Any] | None = None,
 ) -> None:
     if app_dir is not None:
         sys.path.insert(0, app_dir)
@@ -563,6 +564,7 @@ def run(
         use_colors=use_colors,
         factory=factory,
         h11_max_incomplete_event_size=h11_max_incomplete_event_size,
+        factory_kwargs=factory_kwargs,
     )
     server = Server(config=config)