diff --git a/tests/test_response_dependency.py b/tests/test_response_dependency.py index 1c600e484..1153784e7 100644 --- a/tests/test_response_dependency.py +++ b/tests/test_response_dependency.py @@ -1,8 +1,13 @@ -"""Test using Response type hint as dependency annotation.""" +"""Test using special types (Response, Request, BackgroundTasks) as dependency annotations. + +These tests verify that special FastAPI types can be used with Depends() annotations +and that the dependency injection system properly handles them. +""" from typing import Annotated -from fastapi import Depends, FastAPI, Response +from fastapi import BackgroundTasks, Depends, FastAPI, Request, Response +from fastapi.responses import JSONResponse from fastapi.testclient import TestClient @@ -87,3 +92,82 @@ def test_response_dependency_chain(): assert resp.status_code == 200 assert resp.headers.get("X-First") == "1" assert resp.headers.get("X-Second") == "2" + + +def test_response_dependency_returns_different_response_instance(): + """Dependency that returns a different Response instance should work. + + When a dependency returns a new Response object (e.g., JSONResponse) instead + of modifying the injected one, the returned response should be used and any + modifications to it in the endpoint should be preserved. + """ + app = FastAPI() + + def default_response() -> Response: + response = JSONResponse(content={"status": "ok"}) + response.headers["X-Custom"] = "initial" + return response + + @app.get("/") + def endpoint(response: Annotated[Response, Depends(default_response)]): + response.headers["X-Custom"] = "modified" + return response + + client = TestClient(app) + resp = client.get("/") + + assert resp.status_code == 200 + assert resp.json() == {"status": "ok"} + assert resp.headers.get("X-Custom") == "modified" + + +# Tests for Request type hint with Depends +def test_request_with_depends_annotated(): + """Request type hint should work in dependency chain.""" + app = FastAPI() + + def extract_request_info(request: Request) -> dict: + return { + "path": request.url.path, + "user_agent": request.headers.get("user-agent", "unknown"), + } + + @app.get("/") + def endpoint( + info: Annotated[dict, Depends(extract_request_info)], + ): + return info + + client = TestClient(app) + resp = client.get("/", headers={"user-agent": "test-agent"}) + + assert resp.status_code == 200 + assert resp.json() == {"path": "/", "user_agent": "test-agent"} + + +# Tests for BackgroundTasks type hint with Depends +def test_background_tasks_with_depends_annotated(): + """BackgroundTasks type hint should work with Annotated[BackgroundTasks, Depends(...)].""" + app = FastAPI() + task_results = [] + + def background_task(message: str): + task_results.append(message) + + def add_background_task(background_tasks: BackgroundTasks) -> BackgroundTasks: + background_tasks.add_task(background_task, "from dependency") + return background_tasks + + @app.get("/") + def endpoint( + background_tasks: Annotated[BackgroundTasks, Depends(add_background_task)], + ): + background_tasks.add_task(background_task, "from endpoint") + return {"status": "ok"} + + client = TestClient(app) + resp = client.get("/") + + assert resp.status_code == 200 + assert "from dependency" in task_results + assert "from endpoint" in task_results