You could want to set up a different database for testing, rollback the data after the tests, pre-fill it with some testing data, etc.

The main idea is exactly the same you saw in that previous chapter.

## Add tests for the SQL app

# 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).

testing-pyramid.png...

为此，要在 `with` 语句中使用 `TestClient` 连接 WebSocket。

```Python hl_lines="27-31"
{!../../../docs_src/app_testing/tutorial002.py!}
```

!!! note "笔记"

```Python hl_lines="27-31"
{!../../../docs_src/app_testing/tutorial002.py!}
```

!!! note "Hinweis"

Paul Merlin <******@****.***> 1690890212 +0200

Nils Lindemann <******@****.***> 1713469999 +0200

# limitations under the License.

# This script checks whether the testing.init symbol is present in any
# of the release binaries and fails if it finds one. This check is needed
# to avoid including test libraries in production binaries as they often lack
# rigorous review and sufficient testing.
# Usage: `hack/verify-test-code.sh`.

set -o errexit
set -o nounset
set -o pipefail

# 测试数据库

您还可以使用[测试依赖项](testing-dependencies.md){.internal-link target=_blank}中的覆盖依赖项方法变更测试的数据库。

实现设置其它测试数据库、在测试后回滚数据、或预填测试数据等操作。

本章的主要思路与上一章完全相同。

## 为 SQL 应用添加测试

为了使用测试数据库，我们要升级 [SQL 关系型数据库](../tutorial/sql-databases.md){.internal-link target=_blank} 一章中的示例。

应用的所有代码都一样，直接查看那一章的示例代码即可。

本章只是新添加了测试文件。

正常的依赖项 `get_db()` 返回数据库会话。

测试时使用覆盖依赖项返回自定义数据库会话代替正常的依赖项。

本例中，要创建仅用于测试的临时数据库。

## 文件架构

Nils Lindemann <******@****.***> 1711830001 +0100