}


def test_read_item_bad_token():
    response = client.get("/items/foo", headers={"X-Token": "hailhydra"})
    assert response.status_code == 400
    assert response.json() == {"detail": "Invalid X-Token header"}


def test_read_nonexistent_item():
    response = client.get("/items/baz", headers={"X-Token": "coneofsilence"})
    assert response.status_code == 404
    assert response.json() == {"detail": "Item not found"}

def test_security_http_basic_non_basic_credentials():
    payload = b64encode(b"johnsecret").decode("ascii")
    auth_header = f"Basic {payload}"
    response = client.get("/users/me", headers={"Authorization": auth_header})
    assert response.status_code == 401, response.text
    assert response.headers["WWW-Authenticate"] == "Basic"

```Python
from .dependencies import get_token_header
```

would mean:

* Starting in the same package that this module (the file `app/routers/items.py`) lives in (the directory `app/routers/`)...
* find the module `dependencies` (an imaginary file at `app/routers/dependencies.py`)...
* and from it, import the function `get_token_header`.

def test_security_http_basic_non_basic_credentials():
    payload = b64encode(b"johnsecret").decode("ascii")
    auth_header = f"Basic {payload}"
    response = client.get("/users/me", headers={"Authorization": auth_header})
    assert response.status_code == 401, response.text
    assert response.headers["WWW-Authenticate"] == 'Basic realm="simple"'

First, we create a `GzipRequest` class, which will overwrite the `Request.body()` method to decompress the body in the presence of an appropriate header.

If there's no `gzip` in the header, it will not try to decompress the body.

That way, the same route class can handle gzip compressed or uncompressed requests.

```Python hl_lines="8-15"

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient

from docs_src.header_params.tutorial003_an import app

client = TestClient(app)


@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"X-Token values": None}),
        ("/items", {"x-token": "foo"}, 200, {"X-Token values": ["foo"]}),
        # TODO: fix this, is it a bug?

            data = websocket.receive_text()
            assert data == f"Message text was: {message}, for item ID: foo"


@needs_py39
def test_websocket_with_header(app: FastAPI):
    client = TestClient(app)
    with pytest.raises(WebSocketDisconnect):
        with client.websocket_connect("/items/bar/ws?token=some-token") as websocket:
            message = "Message one"

    * But it needs authentication for that specific endpoint.
    * So, to authenticate with our API, it sends a header `Authorization` with a value of `Bearer ` plus the token.
    * If the token contains `foobar`, the content of the `Authorization` header would be: `Bearer foobar`.

## **FastAPI**'s `OAuth2PasswordBearer`

```Python
from ..dependencies import get_token_header
```

表示：

* 从该模块（`app/routers/items.py` 文件）所在的同一个包（`app/routers/` 目录）开始...
* 跳转到其父包（`app/` 目录）...
* 在该父包中，找到 `dependencies` 模块（位于 `app/dependencies.py` 的文件）...
* 然后从中导入函数 `get_token_header`。

正常工作了！🎉

---

同样，如果我们使用了三个点 `...`，例如：

```Python
from ...dependencies import get_token_header
```

那将意味着：

@app.get("/items/{item_id}")
async def read_item(item_id: str):
    if item_id not in items:
        raise HTTPException(
            status_code=404,
            detail="Item not found",
            headers={"X-Error": "Some custom header"},
        )
    return {"item": items[item_id]}


@app.get("/http-no-body-statuscode-exception")
async def no_body_status_code_exception():
    raise HTTPException(status_code=204)