client = TestClient(mod.app)
    response = client.post("/token", data={"username": "johndoe", "password": "secret"})
    assert response.status_code == 200, response.text
    content = response.json()
    assert "access_token" in content
    assert content["token_type"] == "bearer"


def test_login_incorrect_password(mod: ModuleType):
    client = TestClient(mod.app)
    response = client.post(

from fastapi import Depends, FastAPI

app = FastAPI()


async def common_parameters(q: str | None = None, skip: int = 0, limit: int = 100):
    return {"q": q, "skip": skip, "limit": limit}


@app.get("/items/")
async def read_items(commons: dict = Depends(common_parameters)):
    return commons


@app.get("/users/")
async def read_users(commons: dict = Depends(common_parameters)):

from fastapi import FastAPI
from fastapi.responses import FileResponse

some_file_path = "large-video-file.mp4"
app = FastAPI()


@app.get("/")
async def main():

from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class JsonApiResponse(JSONResponse):
    media_type = "application/vnd.api+json"


class Error(BaseModel):
    status: str
    title: str


class JsonApiError(BaseModel):
    errors: list[Error]


@app.get(
    "/a",
    response_class=Response,

在实际应用中，你可能会把你的测试放在另一个文件里。

您的**FastAPI**应用程序也可能由一些文件/模块组成等等。

### **FastAPI** app 文件

假设你有一个像 [更大的应用](bigger-applications.md){.internal-link target=_blank} 中所描述的文件结构:

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

在 `main.py` 文件中你有一个 **FastAPI** app:


{* ../../docs_src/app_testing/main.py *}

### 测试文件

然后你会有一个包含测试的文件 `test_main.py` 。app可以像Python包那样存在（一样是目录，但有个 `__init__.py` 文件）：

``` hl_lines="5"
.

@flask_app.route("/")
def flask_main():
    name = request.args.get("name", "World")
    return f"Hello, {escape(name)} from Flask!"


app = FastAPI()


@app.get("/v2")
def read_main():
    return {"message": "Hello World"}

from fastapi.testclient import TestClient

from .main import app

client = TestClient(app)


def test_read_main():
    response = client.get("/")
    assert response.status_code == 200

from typing import Union

from fastapi import Cookie, FastAPI

app = FastAPI()


@app.get("/items/")
async def read_items(ads_id: Union[str, None] = Cookie(default=None)):

from typing import Union

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Union[str, None] = Header(default=None)):

from typing import Annotated

from fastapi import FastAPI, Form

app = FastAPI()


@app.post("/login/")
async def login(username: Annotated[str, Form()], password: Annotated[str, Form()]):