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node.js - Jest: Find out if current module is mocked during runtime

问题描述

Is there a way i can find out during runtime if a module is mocked via jest?

Since mocked modules get required normally and therefore the code gets executed (as seen here: jest module executed even when mocked

We need this because we have checks on top of each file to fail early when a mandatory environment variable is not set, which causes our tests to fail even if the module is mocked.

if (!process.env.SOME_ENV) {
  throw new Error(`Mandatory environment variable 'SOME_ENV' not set`)
}

We are looking for something like this:

if (!process.env.SOME_ENV && utils.isNotMocked(this)) {
  throw new Error(`Mandatory environment variable 'SOME_ENV' not set`)
}

where utils.isNotMocked(this) is the magic function which checks if the module is currently mocked.

标签： node.jsunit-testingmockingjestjs

解决方案

正如@jonrsharpe 提到的，通常不希望软件能够区分它是否在测试中。这意味着，您可能不会在任何模拟框架中找到您希望的功能。此外，提供这样一个特性可能存在更多基本问题，因为您可能有混合测试场景，其中某些测试用例使用模拟类的对象，而其他测试用例使用原始类的对象。

由于您在代码中使用早期退出机制作为一般模式，正如您所描述的那样：为此检查创建一个库函数怎么样 - 然后可以在测试期间再次加倍，以便在这种情况下函数不会抛出？

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