Add client parameter to TestClient

docs/testclient.md

@@ -69,6 +69,11 @@ case you should use `client = TestClient(app, raise_server_exceptions=False)`.
     not be triggered when the `TestClient` is instantiated. You can learn more about it
     [here](lifespan.md#running-lifespan-in-tests).
 
+!!! note
+
+    By default the `TestClient` uses `testclient:50000` as the host and port. 
+    To use a different client, you can pass the host and port as a tuple: `TestClient(client=(<host>, <port>)`.
+
 ### Selecting the Async backend
 
 `TestClient` takes arguments `backend` (a string) and `backend_options` (a dictionary).

starlette/testclient.py

@@ -234,13 +234,15 @@ def __init__(
         raise_server_exceptions: bool = True,
         root_path: str = "",
         *,
+        client: tuple[str, int],
         app_state: dict[str, typing.Any],
     ) -> None:
         self.app = app
         self.raise_server_exceptions = raise_server_exceptions
         self.root_path = root_path
         self.portal_factory = portal_factory
         self.app_state = app_state
+        self.client = client
 
     def handle_request(self, request: httpx.Request) -> httpx.Response:
         scheme = request.url.scheme
@@ -285,7 +287,7 @@ def handle_request(self, request: httpx.Request) -> httpx.Response:
                 "scheme": scheme,
                 "query_string": query.encode(),
                 "headers": headers,
-                "client": ["testclient", 50000],
+                "client": self.client,
                 "server": [host, port],
                 "subprotocols": subprotocols,
                 "state": self.app_state.copy(),
@@ -304,7 +306,7 @@ def handle_request(self, request: httpx.Request) -> httpx.Response:
             "scheme": scheme,
             "query_string": query.encode(),
             "headers": headers,
-            "client": ["testclient", 50000],
+            "client": self.client,
             "server": [host, port],
             "extensions": {"http.response.debug": {}},
             "state": self.app_state.copy(),
@@ -409,6 +411,7 @@ def __init__(
         cookies: httpx._types.CookieTypes | None = None,
         headers: dict[str, str] | None = None,
         follow_redirects: bool = True,
+        client: tuple[str, int] = ("testclient", 50000),
     ) -> None:
         self.async_backend = _AsyncBackend(backend=backend, backend_options=backend_options or {})
         if _is_asgi3(app):
@@ -424,6 +427,7 @@ def __init__(
             raise_server_exceptions=raise_server_exceptions,
             root_path=root_path,
             app_state=self.app_state,
+            client=client,
         )
         if headers is None:
             headers = {}

tests/test_testclient.py

@@ -282,6 +282,19 @@ async def app(scope: Scope, receive: Receive, send: Send) -> None:
     assert response.json() == {"host": "testclient", "port": 50000}
 
 
+def test_client_custom_client(test_client_factory: TestClientFactory) -> None:
+    async def app(scope: Scope, receive: Receive, send: Send) -> None:
+        client = scope.get("client")
+        assert client is not None
+        host, port = client
+        response = JSONResponse({"host": host, "port": port})
+        await response(scope, receive, send)
+
+    client = test_client_factory(app, client=("192.168.0.1", 3000))
+    response = client.get("/")
+    assert response.json() == {"host": "192.168.0.1", "port": 3000}
+
+
 @pytest.mark.parametrize("param", ("2020-07-14T00:00:00+00:00", "España", "voilà"))
 def test_query_params(test_client_factory: TestClientFactory, param: str) -> None:
     def homepage(request: Request) -> Response:

tests/types.py

@@ -19,6 +19,7 @@ def __call__(
             cookies: httpx._types.CookieTypes | None = None,
             headers: dict[str, str] | None = None,
             follow_redirects: bool = True,
+            client: tuple[str, int] = ("testclient", 50000),
         ) -> TestClient: ...
 else:  # pragma: no cover