Refactor: Move examples to tests and export route_middleware at package level

docs_src/route_middleware/tutorial001.py

@@ -1,13 +1,27 @@
-from fastapi import FastAPI, Request
-from fastapi.route_middleware import log_route, route_middleware, verify_jwt
+from fastapi import FastAPI, Request, route_middleware
 
 app = FastAPI()
 
 
+# You can define your own middlewares
+async def verify_jwt(req: Request):
+    if req.query_params.get("token") != "secret":
+        from fastapi import HTTPException, status
+
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN, detail="Invalid Token"
+        )
+    req.scope["user"] = "admin"
+
+
+def log_route(req: Request):
+    print(f"Request to: {req.url.path}")
+
+
 @app.post("/secure")
 @route_middleware(verify_jwt, log_route)
 async def secure_route(req: Request, is_true: bool):
-    return {"status": "ok", "is_true": is_true, "user": req.user}
+    return {"status": "ok", "is_true": is_true, "user": req.scope.get("user")}
 
 
 @app.post("/open")

fastapi/__init__.py

@@ -20,6 +20,7 @@ from .param_functions import Query as Query
 from .param_functions import Security as Security
 from .requests import Request as Request
 from .responses import Response as Response
+from .route_middleware import route_middleware as route_middleware
 from .routing import APIRouter as APIRouter
 from .websockets import WebSocket as WebSocket
 from .websockets import WebSocketDisconnect as WebSocketDisconnect

fastapi/route_middleware.py

@@ -1,13 +1,11 @@
 from functools import wraps
-from typing import Callable
+from typing import Any, Callable
 
-from fastapi import Request
 
-
-def route_middleware(*middlewares: Callable):
-    def decorator(route_func: Callable):
+def route_middleware(*middlewares: Callable[..., Any]) -> Callable[..., Any]:
+    def decorator(route_func: Callable[..., Any]) -> Callable[..., Any]:
         @wraps(route_func)
-        async def wrapper(*args, **kwargs):
+        async def wrapper(*args: Any, **kwargs: Any) -> Any:
             req = kwargs.get("req")
             if req is None:
                 raise ValueError("Route must have 'request: Request' parameter")
@@ -22,17 +20,3 @@ def route_middleware(*middlewares: Callable):
         return wrapper
 
     return decorator
-
-
-# Example middlewares
-async def verify_jwt(req: Request):
-    # just a mock
-    if not (req.query_params.get("is_true") == "true"):
-        req.user = {"name": "xyz", "admin": True}
-        from fastapi import HTTPException, status
-
-        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Invalid JWT")
-
-
-def log_route(req: Request):
-    print(f"[LOG] Path: {req.url.path}")

tests/test_route_middleware.py

@@ -1,14 +1,29 @@
+import pytest
 from fastapi import FastAPI, Request
-from fastapi.route_middleware import log_route, route_middleware, verify_jwt
+from fastapi.route_middleware import route_middleware
 from fastapi.testclient import TestClient
 
+
+# Example middlewares for testing
+async def verify_jwt(req: Request):
+    if not (req.query_params.get("is_true") == "true"):
+        req.scope["user"] = {"name": "xyz", "admin": True}
+        from fastapi import HTTPException, status
+
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Invalid JWT")
+
+
+def log_route(req: Request):
+    print(f"[LOG] Path: {req.url.path}")
+
+
 app = FastAPI()
 
 
 @app.post("/secure")
 @route_middleware(verify_jwt, log_route)
 async def secure_route(req: Request, is_true: bool):
-    return {"status": "ok", "is_true": is_true, "user": req.user}
+    return {"status": "ok", "is_true": is_true, "user": req.scope.get("user")}
 
 
 @app.post("/open")
@@ -32,3 +47,19 @@ def test_secure_route_fail():
 def test_open_route():
     response = client.post("/open?is_true=false")
     assert response.status_code == 200
+
+
+def test_route_middleware_wrong_param_name():
+    # If the param name is not 'req', it should fail
+    # We use a separate app to avoid polluting the main 'app'
+    local_app = FastAPI()
+
+    @local_app.get("/wrong-param")
+    @route_middleware(log_route)
+    async def wrong_param_handler(request: Request):
+        return {"msg": "ok"}  # pragma: no cover
+
+    with pytest.raises(
+        ValueError, match="Route must have 'request: Request' parameter"
+    ):
+        TestClient(local_app).get("/wrong-param")