每次 Karma 测试后如何清理？

Question

This is my test (Karma + Mocha):

describe('foo', function() {
  afterEach(function() {
    var id = window.setTimeout(function() {}, 0);
    while (id--) {
      window.clearTimeout(id);
    }
  });
  it('works', function() {
    document.body.innerHTML = '<html/>';
    // add some timeouts here
  });
});

The afterEach part is exactly the same in all tests. It cleans up the mess after the test. It's obvious code duplication. How can I get rid of it?

Answer 1

You can run a global hook ( before , beforeEach , after and afterEach ) when running each test by defining a method in a setup file.

test/setup.js

beforeEach(async () => {  
  // your code
})

We need to tell Mocha where we can find this file, we can do this by placing the following in the mocha.opts ( https://mochajs.org/#mochaopts ) file.

--file ./test/setup.js

You can read more about it here: https://mochajs.org/#root-level-hooks .