对于这些用例，**FastAPI** 应用支持 `app.dependcy_overrides` 属性，该属性就是**字典**。

要在测试时覆盖原有依赖项，这个字典的键应当是原依赖项（函数），值是覆盖依赖项（另一个函数）。

这样一来，**FastAPI** 就会调用覆盖依赖项，不再调用原依赖项。

```Python hl_lines="26-27  30"
{!../../../docs_src/dependency_testing/tutorial001.py!}
```

!!! tip "提示"

    **FastAPI** 应用中的任何位置都可以实现覆盖依赖项。

    原依赖项可用于*路径操作函数*、*路径操作装饰器*（不需要返回值时）、`.include_router()` 调用等。

    FastAPI 可以覆盖这些位置的依赖项。

🔐 🔗 🔬, 👆 🚮 🔑 ⏮️ 🔗 (🔢), & 💲, 👆 🔗 🔐 (➕1️⃣ 🔢).

& ⤴️ **FastAPI** 🔜 🤙 👈 🔐 ↩️ ⏮️ 🔗.

```Python hl_lines="28-29  32"
{!../../../docs_src/dependency_testing/tutorial001.py!}
```

!!! tip
    👆 💪 ⚒ 🔗 🔐 🔗 ⚙️ 🙆 👆 **FastAPI** 🈸.

    ⏮️ 🔗 💪 ⚙️ *➡ 🛠️ 🔢*, *➡ 🛠️ 👨‍🎨* (🕐❔ 👆 🚫 ⚙️ 📨 💲), `.include_router()` 🤙, ♒️.

    FastAPI 🔜 💪 🔐 ⚫️.

# 🔬 💽

👆 💪 ⚙️ 🎏 🔗 🔐 ⚪️➡️ [🔬 🔗 ⏮️ 🔐](testing-dependencies.md){.internal-link target=_blank} 📉 💽 🔬.

👆 💪 💚 ⚒ 🆙 🎏 💽 🔬, 💾 💽 ⏮️ 💯, 🏤-🥧 ⚫️ ⏮️ 🔬 💽, ♒️.

👑 💭 ⚫️❔ 🎏 👆 👀 👈 ⏮️ 📃.

## 🚮 💯 🗄 📱

➡️ ℹ 🖼 ⚪️➡️ [🗄 (🔗) 💽](../tutorial/sql-databases.md){.internal-link target=_blank} ⚙️ 🔬 💽.

🌐 📱 📟 🎏, 👆 💪 🚶 🔙 👈 📃 ✅ ❔ ⚫️.

🕴 🔀 📥 🆕 🔬 📁.

👆 😐 🔗 `get_db()` 🔜 📨 💽 🎉.

from ...utils import needs_py39


@needs_py39
def test_override_in_items_run():
    from docs_src.dependency_testing.tutorial001_an_py39 import test_override_in_items

    test_override_in_items()


@needs_py39
def test_override_in_items_with_q_run():
    from docs_src.dependency_testing.tutorial001_an_py39 import (
        test_override_in_items_with_q,
    )

    test_override_in_items_with_q()


@needs_py39

## Beispiel

Betrachten wir als einfaches Beispiel eine Dateistruktur ähnlich der in [Größere Anwendungen](../tutorial/bigger-applications.md){.internal-link target=_blank} und [Testen](../tutorial/testing.md){.internal-link target=_blank}:

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

Die Datei `main.py` hätte als Inhalt:

```Python

## 🖼

🙅 🖼, ➡️ 🤔 📁 📊 🎏 1️⃣ 🔬 [🦏 🈸](../tutorial/bigger-applications.md){.internal-link target=_blank} & [🔬](../tutorial/testing.md){.internal-link target=_blank}:

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

📁 `main.py` 🔜 ✔️:

```Python
{!../../../docs_src/async_tests/main.py!}
```

* Update docs for testing FastAPI. Include using `POST`, sending JSON, testing headers, etc. New documentation: [Testing](https://fastapi.tiangolo.com/tutorial/testing/#testing-extended-example). PR [#271](https://github.com/tiangolo/fastapi/pull/271).

### Atualizando as versões FastAPI

Você pode adicionar testes em sua aplicação.

Com o **FastAPI** é muito fácil (graças ao Starlette), verifique a documentação: [Testando](tutorial/testing.md){.internal-link target=_blank}

Após você ter os testes, então você pode fazer o _upgrade_ da versão **FastAPI** para uma mais recente, e ter certeza que todo seu código esteja funcionando corretamente rodando seus testes.

# Testing Dependencies with Overrides

## Overriding dependencies during testing

There are some scenarios where you might want to override a dependency during testing.

You don't want the original dependency to run (nor any of the sub-dependencies it might have).

    ```Python hl_lines="26-27  30"
    {!> ../../../docs_src/dependency_testing/tutorial001_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="28-29  32"
    {!> ../../../docs_src/dependency_testing/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="29-30  33"
    {!> ../../../docs_src/dependency_testing/tutorial001_an.py!}
    ```

=== "Python 3.10+ nicht annotiert"