用Jest重置单个模块 [英] Reset single module with Jest

问题描述

jest.resetModules()清除所有模块的require缓存，但是有没有办法只清除单个模块呢?无法使用 require.cache ，因为Jest似乎绕过了它.

jest.resetModules() clears the require cache for all modules but is there a way to clear it for just a single module? Can't use require.cache as Jest appears to bypass it.

我正在测试有状态的Node模块(即，它依赖于对 require 的多次调用返回相同实例的事实).对于我的测试，我需要重置模块的状态以测试不同的场景. jest.resetModules()可以工作，但是随后我需要重新 require 一些其他不需要重置的模拟模块.

I'm testing a Node module which is stateful (i.e. it relies on the fact that multiple calls to require return the same instance). For my test I need to reset the state of the module to test different scenarios. jest.resetModules() works but then I need to re-require some other mocked modules which didn't need to be reset.

推荐答案

自Jest 24开始，您现在可以使用 jest.isolateModules 来做到这一点.

Since Jest 24 you can now use the jest.isolateModules to do this.

假设您只想重置某个模块，那么您应该在 jest.isolateModules 的回调中要求该模块:

Let's say you only want to reset a certain module, then you should require that in the callback of jest.isolateModules:

let myModule;
jest.isolateModules(() => {
  myModule = require('my-certain-module');
});

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