我开始认为这是不可能的，但是无论如何我都想问。

我想测试我的一个ES6模块以特定方式调用另一个ES6模块。有了茉莉花，这非常容易-

应用程式码：

// myModule.js
import dependency from './dependency';

export default (x) => {
  dependency.doSomething(x * 2);
}

和测试代码：

//myModule-test.js
import myModule from '../myModule';
import dependency from '../dependency';

describe('myModule', () => {
  it('calls the dependency with double the input', () => {
    spyOn(dependency, 'doSomething');

    myModule(2);

    expect(dependency.doSomething).toHaveBeenCalledWith(4);
  });
});

笑话相当于什么？我觉得这是一件很想做的简单的事，但是我一直在努力尝试弄清头发。

我最接近的是将imports 替换为requires，并将其移入测试/函数中。都不是我想做的事情。

// myModule.js
export default (x) => {
  const dependency = require('./dependency'); // yuck
  dependency.doSomething(x * 2);
}

//myModule-test.js
describe('myModule', () => {
  it('calls the dependency with double the input', () => {
    jest.mock('../dependency');

    myModule(2);

    const dependency = require('../dependency'); // also yuck
    expect(dependency.doSomething).toBeCalledWith(4);
  });
});

For bonus points, I'd love to make the whole thing work when the function inside dependency.js is a default export. However, I know that spying on default exports doesn't work in Jasmine (or at least I could never get it to work), so I'm not holding out hope that it's possible in Jest either.