✨ Add support for custom route class (#468)

fastapi/routing.py

@@ -317,11 +317,13 @@ class APIRouter(routing.Router):
         redirect_slashes: bool = True,
         default: ASGIApp = None,
         dependency_overrides_provider: Any = None,
+        route_class: Type[APIRoute] = APIRoute,
     ) -> None:
         super().__init__(
             routes=routes, redirect_slashes=redirect_slashes, default=default
         )
         self.dependency_overrides_provider = dependency_overrides_provider
+        self.route_class = route_class
 
     def add_api_route(
         self,
@@ -347,7 +349,7 @@ class APIRouter(routing.Router):
         response_class: Type[Response] = JSONResponse,
         name: str = None,
     ) -> None:
-        route = APIRoute(
+        route = self.route_class(
             path,
             endpoint=endpoint,
             response_model=response_model,