如何确保Jest在"unhandledRejection"上失败? [英] How to ensure Jest fails on "unhandledRejection"?

问题描述

我们的单元测试在连续交付管道中的容器中运行.

Our unit tests run in containers in our continuous delivery pipelines.

有时候，我们不会在单元测试中处理拒绝，但是，我认为这是不正确的，并且我认为管道应该会失败.

Sometimes, we don't handle rejections in our unit tests, however, I don't think it's correct and in my opinion the pipeline should fail.

如何确保在执行jest并在测试过程中发生unhandledRejection事件，玩笑会退出并显示错误?

How can I make sure that when I execute jest and during the tests an unhandledRejection event occurs, jest will exit with error?

我试图将事件监听器挂在安装脚本中:

I tried to hook event listeners in a setup script:

/* jest.config.js */
module.exports = {
    setupFiles: ['<rootDir>/test/setup.ts'],
    // ...
}

在该设置脚本中，我可以检测到unhandledRejection事件，但不幸的是，我无法开玩笑

and in that setup script, I can detect unhandledRejection events, but unfortunately, I can't make jest break

process.on('unhandledRejection', () => {
    console.error('Now what?');
    console.error('I want to make sure that jest exits with an error!');
});

推荐答案

您可以创建一个笑话配置文件jest.config.js并将以下条目放入其中:

You can create a jest config file jest.config.js and put the following entry into it:

module.exports = {
  ...
  setupFiles: ['<rootDir>/test/setup.js'],
  ...
};

然后在您的setup.js文件中，您可以执行以下操作:

And then in your setup.js file, you can do something like this:

process.on('unhandledRejection', (err) => {
  fail(err);
});

unhandledRejection将失败，尽管有两个注意事项:

And unhandledRejection will fail a test, though there are two caveates to be aware of:

1. 未执行测试时拒绝的承诺中未处理的拒绝将结束该过程.这可能就是您想要和期望的.
2. 未处理的来自承诺的拒绝会在新测试正在运行时拒绝(而不是发起承诺的那个)将使新测试(而不是原始测试)失败.这令人困惑，并且可能导致难以跟踪错误.

作为上面提到的评论者，如果您的测试写得很好，那么您永远都不会遇到这种情况，但是您并不总是拥有那么多的控制权.

As a commenter mentioned above, if your tests are well written, then you should never hit this scenario, but you don't always have that much control.

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