Allow dependency injection Config and Server

tests/test_config.py

@@ -516,7 +516,10 @@ def test_ws_max_size() -> None:
 def test_bind_unix_socket_works_with_reload_or_workers(tmp_path, reload, workers):
     uds_file = tmp_path / "uvicorn.sock"
     config = Config(
-        app=asgi_app, uds=uds_file.as_posix(), reload=reload, workers=workers
+        app="tests.test_config:asgi_app",
+        uds=uds_file.as_posix(),
+        reload=reload,
+        workers=workers,
     )
     config.load()
     sock = config.bind_socket()
@@ -538,7 +541,12 @@ def test_bind_unix_socket_works_with_reload_or_workers(tmp_path, reload, workers
 def test_bind_fd_works_with_reload_or_workers(reload, workers):
     fdsock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
     fd = fdsock.fileno()
-    config = Config(app=asgi_app, fd=fd, reload=reload, workers=workers)
+    config = Config(
+        app="tests.test_config:asgi_app",
+        fd=fd,
+        reload=reload,
+        workers=workers,
+    )
     config.load()
     sock = config.bind_socket()
     assert isinstance(sock, socket.socket)

tests/test_main.py

@@ -48,7 +48,12 @@ async def test_run(host, url):
 
 @pytest.mark.asyncio
 async def test_run_multiprocess():
-    config = Config(app=app, loop="asyncio", workers=2, limit_max_requests=1)
+    config = Config(
+        app="tests.test_main:app",
+        loop="asyncio",
+        workers=2,
+        limit_max_requests=1,
+    )
     async with run_server(config):
         async with httpx.AsyncClient() as client:
             response = await client.get("http://127.0.0.1:8000")
@@ -57,7 +62,12 @@ async def test_run_multiprocess():
 
 @pytest.mark.asyncio
 async def test_run_reload():
-    config = Config(app=app, loop="asyncio", reload=True, limit_max_requests=1)
+    config = Config(
+        app="tests.test_main:app",
+        loop="asyncio",
+        reload=True,
+        limit_max_requests=1,
+    )
     async with run_server(config):
         async with httpx.AsyncClient() as client:
             response = await client.get("http://127.0.0.1:8000")

uvicorn/__init__.py

@@ -1,5 +1,5 @@
 from uvicorn.config import Config
-from uvicorn.main import Server, main, run
+from uvicorn.main import Server, main, run, run_server
 
 __version__ = "0.15.0"
-__all__ = ["main", "run", "Config", "Server"]
+__all__ = ["main", "run", "run_server", "Config", "Server"]

uvicorn/config.py

@@ -444,6 +444,13 @@ def load(self) -> None:
 
         self.lifespan_class = import_from_string(LIFESPAN[self.lifespan])
 
+        if (self.reload or self.workers > 1) and not isinstance(self.app, str):
+            logger.warning(
+                "You must pass the application as an import string to enable"
+                " 'reload' or 'workers'."
+            )
+            sys.exit(1)
+
         try:
             self.loaded_app = import_from_string(self.app)
         except ImportFromStringError as exc:

uvicorn/main.py

@@ -429,15 +429,11 @@ def main(
 def run(app: typing.Union[ASGIApplication, str], **kwargs: typing.Any) -> None:
     config = Config(app, **kwargs)
     server = Server(config=config)
+    run_server(server)
 
-    if (config.reload or config.workers > 1) and not isinstance(app, str):
-        logger = logging.getLogger("uvicorn.error")
-        logger.warning(
-            "You must pass the application as an import string to enable 'reload' or "
-            "'workers'."
-        )
-        sys.exit(1)
 
+def run_server(server: Server) -> None:
+    config = server.config
     if config.should_reload:
         sock = config.bind_socket()
         ChangeReload(config, target=server.run, sockets=[sock]).run()