https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

ve JSON body şu şekilde olursa:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

o zaman sizin API'niz faturayı işleyecek ve daha sonra bir noktada `callback_url`'ye (yani *external API*'ye) bir callback request gönderecek:

```
https://www.external.org/events/invoices/2expen51ve
```

# 测试 { #testing }

感谢 [Starlette](https://www.starlette.dev/testclient/)，测试**FastAPI** 应用轻松又愉快。

它基于 [HTTPX](https://www.python-httpx.org)，而HTTPX又是基于Requests设计的，所以很相似且易懂。

有了它，你可以直接与**FastAPI**一起使用 [pytest](https://docs.pytest.org/)。

## 使用 `TestClient` { #using-testclient }

/// info | 信息

要使用 `TestClient`，先要安装 [`httpx`](https://www.python-httpx.org)。

确保你创建并激活一个[虚拟环境](../virtual-environments.md)，然后再安装，例如：

```console

  to you under the Apache License, Version 2.0 (the
  "License"); you may not use this file except in compliance
  with the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing,
  software distributed under the License is distributed on an
  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

{* ../../docs_src/app_testing/tutorial002_py310.py hl[27:31] *}

/// note | Примечание

Подробности смотрите в документации Starlette по [тестированию WebSocket](https://www.starlette.dev/testclient/#testing-websocket-sessions).

  ~
  ~ Licensed under the Apache License, Version 2.0 (the "License");
  ~ you may not use this file except in compliance with the License.
  ~ You may obtain a copy of the License at
  ~
  ~      http://www.apache.org/licenses/LICENSE-2.0
  ~
  ~ Unless required by applicable law or agreed to in writing, software
  ~ distributed under the License is distributed on an "AS IS" BASIS,

  - 🔍 FastAPI'nin kullandığı; veri doğrulama ve ayarlar yönetimi için [Pydantic](https://docs.pydantic.dev).
  - 💾 SQL veritabanı olarak [PostgreSQL](https://www.postgresql.org).
- 🚀 frontend için [React](https://react.dev).
  - 💃 TypeScript, hooks, Vite ve modern bir frontend stack'inin diğer parçalarını kullanır.

- `www_redirect` - Si défini à `True`, les requêtes vers les versions sans www des hôtes autorisés seront redirigées vers leurs équivalents avec www. Valeur par défaut : `True`.

Si une requête entrante n'est pas valide, une réponse `400` sera envoyée.

## `GZipMiddleware` { #gzipmiddleware }

 * clients to trust.
 *
 * For example, in order to establish a secure connection to `https://www.squareup.com/`,
 * these three certificates are used.
 *
 * ```
 * www.squareup.com certificate:
 *
 * Common Name: www.squareup.com
 * Subject Alternative Names: www.squareup.com, squareup.com, account.squareup.com...
 * Validity: 2018-07-03T20:18:17Z – 2019-08-01T20:48:15Z

regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

    - 🔍 [Pydantic](https://docs.pydantic.dev), usado pelo FastAPI, para validação de dados e gerenciamento de configurações.
    - 💾 [PostgreSQL](https://www.postgresql.org) como banco de dados SQL.
- 🚀 [React](https://react.dev) para o frontend.
    - 💃 Usando TypeScript, hooks, Vite, e outras partes de uma _stack_ frontend moderna.