fix BaseHTTPMiddleware when used without Starlette

starlette/applications.py

@@ -1,8 +1,5 @@
 import typing
 
-import anyio
-from anyio.abc import TaskGroup
-
 from starlette.datastructures import State, URLPath
 from starlette.exceptions import ExceptionMiddleware
 from starlette.middleware import Middleware
@@ -39,8 +36,6 @@ class Starlette:
     standard functions, or async functions.
     """
 
-    task_group: TaskGroup
-
     def __init__(
         self,
         debug: bool = False,
@@ -114,9 +109,7 @@ def url_path_for(self, name: str, **path_params: str) -> URLPath:
 
     async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
         scope["app"] = self
-        self.task_group = anyio.create_task_group()
-        async with self.task_group:
-            await self.middleware_stack(scope, receive, send)
+        await self.middleware_stack(scope, receive, send)
 
     # The following usages are now discouraged in favour of configuration
     #  during Starlette.__init__(...)

starlette/middleware/base.py

@@ -22,38 +22,38 @@ async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
             await self.app(scope, receive, send)
             return
 
-        request = Request(scope, receive=receive)
-        response = await self.dispatch_func(request, self.call_next)
-        await response(scope, receive, send)
-
-    async def call_next(self, request: Request) -> Response:
-        send_stream, recv_stream = anyio.create_memory_object_stream()
-        scope = request.scope
-
-        async def coro() -> None:
-            async with send_stream:
-                await self.app(scope, request.receive, send_stream.send)
-
-        scope["app"].task_group.start_soon(coro)
-
-        try:
-            message = await recv_stream.receive()
-        except anyio.EndOfStream:
-            raise RuntimeError("No response returned.")
-
-        assert message["type"] == "http.response.start"
-
-        async def body_stream() -> typing.AsyncGenerator[bytes, None]:
-            async with recv_stream:
-                async for message in recv_stream:
-                    assert message["type"] == "http.response.body"
-                    yield message.get("body", b"")
-
-        response = StreamingResponse(
-            status_code=message["status"], content=body_stream()
-        )
-        response.raw_headers = message["headers"]
-        return response
+        async def call_next(request: Request) -> Response:
+            send_stream, recv_stream = anyio.create_memory_object_stream()
+
+            async def coro() -> None:
+                async with send_stream:
+                    await self.app(scope, request.receive, send_stream.send)
+
+            task_group.start_soon(coro)
+
+            try:
+                message = await recv_stream.receive()
+            except anyio.EndOfStream:
+                raise RuntimeError("No response returned.")
+
+            assert message["type"] == "http.response.start"
+
+            async def body_stream() -> typing.AsyncGenerator[bytes, None]:
+                async with recv_stream:
+                    async for message in recv_stream:
+                        assert message["type"] == "http.response.body"
+                        yield message.get("body", b"")
+
+            response = StreamingResponse(
+                status_code=message["status"], content=body_stream()
+            )
+            response.raw_headers = message["headers"]
+            return response
+
+        async with anyio.create_task_group() as task_group:
+            request = Request(scope, receive=receive)
+            response = await self.dispatch_func(request, call_next)
+            await response(scope, receive, send)
 
     async def dispatch(
         self, request: Request, call_next: RequestResponseEndpoint

starlette/testclient.py

@@ -8,6 +8,7 @@
 import queue
 import types
 import typing
+from concurrent.futures import Future
 from urllib.parse import unquote, urljoin, urlsplit
 
 import anyio
@@ -284,7 +285,7 @@ def __enter__(self) -> "WebSocketTestSession":
         )
 
         try:
-            self.portal.start_task_soon(self._run)
+            _: "Future[None]" = self.portal.start_task_soon(self._run)
             self.send({"type": "websocket.connect"})
             message = self.receive()
             self._raise_on_close(message)
@@ -385,6 +386,8 @@ class TestClient(requests.Session):
         "backend_options": {},
     }  # type: typing.Dict[str, typing.Any]
 
+    task: "Future[None]"
+
     def __init__(
         self,
         app: typing.Union[ASGI2App, ASGI3App],