`TestClient` 在内部通过一些“魔法”操作，使得您可以在普通的 `def` 测试函数中调用异步的 FastAPI 应用程序，并使用标准的 pytest。但当我们在异步函数中使用它时，这种“魔法”就不再生效了。由于测试以异步方式运行，我们无法在测试函数中继续使用 `TestClient`。

`TestClient` 是基于 <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a> 的。幸运的是，我们可以直接使用它来测试API。

## 示例

举个简单的例子，让我们来看一个[更大的应用](../tutorial/bigger-applications.md){.internal-link target=_blank}和[测试](../tutorial/testing.md){.internal-link target=_blank}中描述的类似文件结构：

Sie sehen die automatische API-Dokumentation für die Hauptanwendung, welche nur deren eigene _Pfadoperationen_ anzeigt:

<img src="/img/tutorial/sub-applications/image01.png">

# CORS (Cross-Origin Resource Sharing) { #cors-cross-origin-resource-sharing }

     */
    List<Profile> getActivePomProfiles(String modelId);

    /**
     * Gets the external profiles that were active during model building. External profiles are those that were
     * contributed by {@link ModelBuildingRequest#getProfiles()}.
     *
     * @return The active external profiles or an empty list if none, never {@code null}.
     */
    List<Profile> getActiveExternalProfiles();

    /**

The `TestClient` is based on <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a>, and luckily, we can use it directly to test the API.

## Example { #example }

* <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">External link</a>
* <a href="https://fastapi.tiangolo.com/css/styles.css" class="external-link" target="_blank">Link to a style</a>
* <a href="https://fastapi.tiangolo.com/js/logic.js" class="external-link" target="_blank">Link to a script</a>
* <a href="https://fastapi.tiangolo.com/img/foo.jpg" class="external-link" target="_blank">Link to an image</a>

Любая функция, с которой можно корректно использовать:

* <a href="https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager" class="external-link" target="_blank">`@contextlib.contextmanager`</a> или
* <a href="https://docs.python.org/3/library/contextlib.html#contextlib.asynccontextmanager" class="external-link" target="_blank">`@contextlib.asynccontextmanager`</a>

будет корректной для использования в качестве зависимости **FastAPI**.

그리고 나머지는 **FastAPI**에 의해 처리됩니다.

실행하면 <a href="http://localhost:8000/v1/" class="external-link" target="_blank">http://localhost:8000/v1/</a>으로 이동해서 Flask의 응답을 볼 수 있습니다:

```txt
Hello, World from Flask!
```

그리고 다음으로 이동하면 <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> Flask의 응답을 볼 수 있습니다:

```JSON
{
    "message": "Hello World"
}

# Configure Swagger UI { #configure-swagger-ui }

You can configure some extra <a href="https://swagger.io/docs/open-source-tools/swagger-ui/usage/configuration/" class="external-link" target="_blank">Swagger UI parameters</a>.

To configure them, pass the `swagger_ui_parameters` argument when creating the `FastAPI()` app object or to the `get_swagger_ui_html()` function.

`swagger_ui_parameters` receives a dictionary with the configurations passed to Swagger UI directly.

Вы увидите автоматическую документацию API для основного приложения, включающую только его собственные _операции пути_:

<img src="/img/tutorial/sub-applications/image01.png">