# 避免共享状态

URL: https://deploy-preview-2977--selenium-dev.netlify.app/zh-cn/documentation/test_practices/encouraged/avoid_sharing_state/

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尽管在多个地方都提到过, 但这点仍值得被再次提及. 确保测试相互隔离.

* 不要共享测试数据. 
想象一下有几个测试, 每个测试都会在选择操作执行之前查询数据库中的有效订单. 
如果两个测试采用相同的顺序, 则很可能会出现意外行为.

* 清理应用程序中过时的数据, 这些数据可能会被其他测试. 
例如无效的订单记录.

* 每次测试都创建一个新的WebDriver实例. 
这在确保测试隔离的同时可以保障并行化更为简单.

    * If you choose [pytest](https://pytest.org/) as your test runner, this can be 
    easily done by yielding your driver in a global fixture. This way each test gets its own 
    driver instance, and you can ensure that drivers always quit after a test is finished 
    (pass or fail).