from fastapi.testclient import TestClient
from pydantic import BaseModel, Field

app = FastAPI()


class ResponseModel(BaseModel):
    code: int = 200
    message: str = Field(default_factory=lambda: "Successful operation.")


@app.get(
    "/response_model_has_default_factory_return_dict",
    response_model=ResponseModel,
)
async def response_model_has_default_factory_return_dict():
    return {"code": 200}


@app.get(