Jestjs 笑话：测试内部函数被调用

鉴于以下情况，在执行

bar

函数时，如何确保使用正确的消息调用内部

foo

函数？谢谢

const foo = (message) => console.log(message);

const bar = () => foo('this is a message');

test('test that the foo function is called with the correct message when the bar' +
     ' function is executed', () => {
  bar();
  expect(foo).toHaveBeenCalledWith('this is a message');
});

---

您需要像这样模拟

foo

函数：

let foo = message => console.log(message)

const bar = () => foo('this is a message')

test('test that the foo function is called with the correct message when the bar function is executed', () => {
    foo = jest.fn()
    bar()
    expect(foo).toHaveBeenCalledWith('this is a message')
})

---

谢谢@kaxi1993！我现在意识到这个答案并不能直接回答我的问题，因为我太抽象了。如果你好奇的话，我发布了一个更直接的问题。