node.js - TypeError : expect. createSpy 不是函数

Question

尝试使用 spy 的属性并以此错误结束。

var spy = expect.createSpy();
spy();
expect(spy).toHaveBeenCalled();

错误:

TypeError: expect.createSpy is not a function

Answer 1

chai 不提供 spy ，为此你需要一个类似 Sinon 的库.

有一个名为 sinon-chai 的 Chai 插件这创建了两者的有用组合:

const chai      = require('chai');
const sinon     = require('sinon');
const sinonChai = require('sinon-chai');
const expect    = chai.expect;

chai.use(sinonChai);

// Create the spy, using Sinon.
let spy = sinon.spy();

// Call the spy, so we can test it.
spy();

// Assert that the spy has been called.
expect(spy).to.have.been.called;