@app.get("/explicit", response_class=JSONResponse)
def get_explicit() -> Item:
    return Item(name="widget", price=9.99)


client = TestClient(app)


def test_default_response_class_skips_json_dumps():
    """When no response_class is set, the fast path serializes directly to
    JSON bytes via Pydantic's dump_json and never calls json.dumps."""
    with patch(