from dirty_equals import IsDict
from fastapi.testclient import TestClient

from ...utils import needs_py39


@pytest.fixture(name="client")
def get_client():
    from docs_src.dependencies.tutorial012_an_py39 import app

    client = TestClient(app)
    return client


@needs_py39
def test_get_no_headers_items(client: TestClient):
    response = client.get("/items/")
    assert response.status_code == 422, response.text

from dirty_equals import IsDict
from fastapi.testclient import TestClient

from ...utils import needs_py310


@pytest.fixture(name="client")
def get_client():
    from docs_src.body_multiple_params.tutorial003_py310 import app

    client = TestClient(app)
    return client


@needs_py310
def test_post_body_valid(client: TestClient):
    response = client.put(
        "/items/5",
        json={
            "importance": 2,

        }

        def acceptanceJson = new AcceptedApiChange(
            change.type,
            change.member,
            '[ADD YOUR CUSTOM REASON HERE]',
            change.changes
        )

        def changeId = (change.type + change.member).replaceAll('[^a-zA-Z0-9]', '_')
        Violation violation = Violation.error(

from dirty_equals import IsDict
from fastapi.testclient import TestClient

from ...utils import needs_py310


@pytest.fixture(name="client")
def get_client():
    from docs_src.body_multiple_params.tutorial001_py310 import app

    client = TestClient(app)
    return client


@needs_py310
def test_post_body_q_bar_content(client: TestClient):
    response = client.put("/items/5?q=bar", json={"name": "Foo", "price": 50.5})

class User(BaseModel):
    username: str


def get_current_user(oauth_header: Optional[str] = Security(reusable_oauth2)):
    if oauth_header is None:
        return None
    user = User(username=oauth_header)
    return user


@app.post("/login")
def login(form_data: OAuth2PasswordRequestFormStrict = Depends()):
    return form_data


@app.get("/users/me")

---

如果你正在使用一个第三方库和某些组件（比如：数据库、API、文件系统...）进行通信，第三方库又不支持使用 `await` （目前大多数数据库三方库都是这样），这种情况你可以像平常那样使用 `def` 声明一个路径操作函数，就像这样：

```Python hl_lines="2"
@app.get('/')
def results():
    results = some_library()
    return results
```

---

如果你的应用程序不需要与其他任何东西通信而等待其响应，请使用 `async def`。

---

如果你不清楚，使用 `def` 就好.

---

# 事件：启动 - 关闭

**FastAPI** 支持定义在应用启动前，或应用关闭后执行的事件处理器（函数）。

事件函数既可以声明为异步函数（`async def`），也可以声明为普通函数（`def`）。

!!! warning "警告"

    **FastAPI** 只执行主应用中的事件处理器，不执行[子应用 - 挂载](sub-applications.md){.internal-link target=_blank}中的事件处理器。

## `startup` 事件

使用 `startup` 事件声明 `app` 启动前运行的函数：

```Python hl_lines="8"
{!../../../docs_src/events/tutorial001.py!}
```

本例中，`startup` 事件处理器函数为项目数据库（只是**字典**）提供了一些初始值。

**FastAPI** 支持多个事件处理器函数。

            ]
        }
    )


def test_post_file(tmp_path):
    path = tmp_path / "test.txt"
    path.write_bytes(b"<file content>")

    client = TestClient(app)
    with path.open("rb") as file:
        response = client.post("/files/", files={"file": file})
    assert response.status_code == 200, response.text
    assert response.json() == {"file_size": 14}


def test_post_large_file(tmp_path):

        @field_validator("name")
        def lower_username(cls, name: str, info: ValidationInfo):
            if not name.endswith("A"):
                raise ValueError("name must end in A")
            return name

    async def get_model_c() -> ModelC:
        return ModelC(username="test-user", password="test-password")

    @app.get("/model/{name}", response_model=ModelA)
    async def get_model_a(name: str, model_c=Depends(get_model_c)):

from dirty_equals import IsDict
from fastapi.testclient import TestClient

from ...utils import needs_py39


@pytest.fixture(name="client")
def get_client():
    from docs_src.dependencies.tutorial006_an_py39 import app

    client = TestClient(app)
    return client


@needs_py39
def test_get_no_headers(client: TestClient):
    response = client.get("/items/")
    assert response.status_code == 422, response.text