fix: add a AsyncTestClientTransport for the AsyncTestClient

litestar/testing/client/async_client.py

@@ -7,7 +7,7 @@
 
 from litestar.testing.client.base import BaseTestClient
 from litestar.testing.life_span_handler import LifeSpanHandler
-from litestar.testing.transport import ConnectionUpgradeExceptionError, TestClientTransport
+from litestar.testing.transport import AsyncTestClientTransport, ConnectionUpgradeExceptionError
 from litestar.types import AnyIOBackend, ASGIApp
 
 if TYPE_CHECKING:
@@ -74,7 +74,7 @@ def __init__(
             headers={"user-agent": "testclient"},
             follow_redirects=True,
             cookies=cookies,
-            transport=TestClientTransport(  # type: ignore [arg-type]
+            transport=AsyncTestClientTransport(
                 client=self,
                 raise_server_exceptions=raise_server_exceptions,
                 root_path=root_path,

litestar/testing/client/sync_client.py

@@ -75,7 +75,7 @@ def __init__(
             headers={"user-agent": "testclient"},
             follow_redirects=True,
             cookies=cookies,
-            transport=TestClientTransport(  # type: ignore[arg-type]
+            transport=TestClientTransport(
                 client=self,
                 raise_server_exceptions=raise_server_exceptions,
                 root_path=root_path,

litestar/testing/transport.py

@@ -6,7 +6,7 @@
 from urllib.parse import unquote
 
 from anyio import Event
-from httpx import ByteStream, Response
+from httpx import AsyncBaseTransport, BaseTransport, ByteStream, Response
 
 from litestar.status_codes import HTTP_500_INTERNAL_SERVER_ERROR
 from litestar.testing.websocket_test_session import WebSocketTestSession
@@ -43,7 +43,7 @@
     context: Any | None
 
 
-class TestClientTransport(Generic[T]):
+class BaseTestClientTransport(Generic[T]):
     def __init__(
         self,
         client: T,
@@ -138,18 +138,64 @@
             "server": (host, port),
         }
 
-    def handle_request(self, request: Request) -> Response:
+    def _prepare_request(self, request: Request) -> tuple[dict[str, Any], dict[str, Any]]:
         scope = self.parse_request(request=request)
         if scope["type"] == "websocket":
             scope.update(
                 subprotocols=[value.strip() for value in request.headers.get("sec-websocket-protocol", "").split(",")]
             )
-            session = WebSocketTestSession(client=self.client, scope=cast("WebSocketScope", scope))  # type: ignore[arg-type]
+            session = WebSocketTestSession(client=self.client, scope=cast("WebSocketScope", scope))
             raise ConnectionUpgradeExceptionError(session)
-
         scope.update(method=request.method, http_version="1.1", extensions={"http.response.template": {}})
-
         raw_kwargs: dict[str, Any] = {"stream": BytesIO()}
+        return raw_kwargs, scope
+
+    def _prepare_response(self, request: Request, context: SendReceiveContext, raw_kwargs: dict[str, Any]) -> Response:
+        if not context["response_started"]:  # pragma: no cover
+            if self.raise_server_exceptions:
+                assert context["response_started"], "TestClient did not receive any response."  # noqa: S101
+            return Response(
+                status_code=HTTP_500_INTERNAL_SERVER_ERROR, headers=[], stream=ByteStream(b""), request=request
+            )
+
+        stream = ByteStream(raw_kwargs.pop("stream", BytesIO()).read())
+        response = Response(**raw_kwargs, stream=stream, request=request)
+        setattr(response, "template", context["template"])
+        setattr(response, "context", context["context"])
+        return response
+
+
+class AsyncTestClientTransport(AsyncBaseTransport, BaseTestClientTransport, Generic[T]):
+    async def handle_async_request(self, request: Request) -> Response:
+        raw_kwargs, scope = self._prepare_request(request)
+        try:
+            response_complete = Event()
+            context: SendReceiveContext = {
+                "response_complete": response_complete,
+                "request_complete": False,
+                "raw_kwargs": raw_kwargs,
+                "response_started": False,
+                "template": None,
+                "context": None,
+            }
+            await self.client.app(
+                scope,
+                self.create_receive(request=request, context=context),
+                self.create_send(request=request, context=context),
+            )
+        except BaseException as exc:
+            if self.raise_server_exceptions:
+                raise exc
+            return Response(
+                status_code=HTTP_500_INTERNAL_SERVER_ERROR, headers=[], stream=ByteStream(b""), request=request
+            )
+        else:
+            return self._prepare_response(request, context, raw_kwargs)
+
+
+class TestClientTransport(BaseTransport, BaseTestClientTransport, Generic[T]):
+    def handle_request(self, request: Request) -> Response:
+        raw_kwargs, scope = self._prepare_request(request)
 
         try:
             with self.client.portal() as portal:
@@ -175,18 +221,4 @@
                 status_code=HTTP_500_INTERNAL_SERVER_ERROR, headers=[], stream=ByteStream(b""), request=request
             )
         else:
-            if not context["response_started"]:  # pragma: no cover
-                if self.raise_server_exceptions:
-                    assert context["response_started"], "TestClient did not receive any response."  # noqa: S101
-                return Response(
-                    status_code=HTTP_500_INTERNAL_SERVER_ERROR, headers=[], stream=ByteStream(b""), request=request
-                )
-
-            stream = ByteStream(raw_kwargs.pop("stream", BytesIO()).read())
-            response = Response(**raw_kwargs, stream=stream, request=request)
-            setattr(response, "template", context["template"])
-            setattr(response, "context", context["context"])
-            return response
-
-    async def handle_async_request(self, request: Request) -> Response:
-        return self.handle_request(request=request)
+            return self._prepare_response(request, context, raw_kwargs)

litestar/testing/websocket_test_session.py

@@ -11,6 +11,7 @@
 from litestar.status_codes import WS_1000_NORMAL_CLOSURE
 
 if TYPE_CHECKING:
+    from litestar.testing.client.async_client import AsyncTestClient
     from litestar.testing.client.sync_client import TestClient
     from litestar.types import (
         WebSocketConnectEvent,
@@ -29,7 +30,7 @@ class WebSocketTestSession:
 
     def __init__(
         self,
-        client: TestClient[Any],
+        client: TestClient[Any] | AsyncTestClient[Any],
         scope: WebSocketScope,
     ) -> None:
         self.client = client

tests/unit/test_testing/test_lifespan_handler.py

@@ -1,6 +1,9 @@
+from asyncio import get_event_loop
+
 import pytest
 
-from litestar.testing import TestClient
+from litestar import Litestar, get
+from litestar.testing import AsyncTestClient, TestClient
 from litestar.testing.life_span_handler import LifeSpanHandler
 from litestar.types import Receive, Scope, Send
 
@@ -35,3 +38,17 @@ async def app(scope: Scope, receive: Receive, send: Send) -> None:
         handler = LifeSpanHandler(TestClient(app))
         await handler.wait_shutdown()
         handler.close()
+
+
+async def test_multiple_clients_event_loop() -> None:
+    @get("/")
+    def return_loop_id() -> dict:
+        return {"loop_id": id(get_event_loop())}
+
+    app = Litestar(route_handlers=[return_loop_id])
+
+    async with AsyncTestClient(app) as client_1, AsyncTestClient(app) as client_2:
+        response_1 = await client_1.get("/")
+        response_2 = await client_2.get("/")
+
+    assert response_1.json() == response_2.json()  # FAILS