如何模拟对象创建及其方法

Question

new UrlBuilder(urlString).buildURL(params).getShortenedURL().then(data => {
  .....
});

如何存根对象创建并检查是否已调用[C​​0]？

我尝试过

getShortenedURL()

但是每次我运行的测试都具有：

this.urlBuilder = sinon.stub(UrlBuilder.prototype, getShortenedURL).resolves({url: '/someUrl'});

会说

assert(this.urlBuilder.getShortenedURL.called);

Answer 1

这是单元测试解决方案：

ReferenceError: getShortenedURL is not defined ：

index.js

const UrlBuilder = require('./urlBuilder');

function main() {
  const urlString = 'https://stackoverflow.com/';
  const params = {};
  return new UrlBuilder(urlString)
    .buildURL(params)
    .getShortenedURL()
    .then((data) => data);
}

module.exports = main;

：

urlBuilder.js

class UrlBuilder {
  constructor(url) {
    this.url = url;
  }
  buildURL(params) {
    return this;
  }
  getShortenedURL() {
    return Promise.resolve('real data');
  }
}

module.exports = UrlBuilder;

：

index.test.js

带有覆盖率报告的单元测试结果：

const sinon = require('sinon');
const proxyquire = require('proxyquire');
const { expect } = require('chai');

describe('60214679', () => {
  it('should pass', async () => {
    const urlBuilderInstanceStub = {
      buildURL: sinon.stub().returnsThis(),
      getShortenedURL: sinon.stub().resolves('fake data'),
    };
    const urlBuilderStub = sinon.stub().callsFake(() => urlBuilderInstanceStub);
    const main = proxyquire('./', {
      './urlBuilder': urlBuilderStub,
    });
    const actual = await main();
    expect(actual).to.be.eq('fake data');
    sinon.assert.calledWithExactly(urlBuilderStub, 'https://stackoverflow.com/');
    sinon.assert.calledWithExactly(urlBuilderInstanceStub.buildURL, {});
    sinon.assert.calledOnce(urlBuilderInstanceStub.getShortenedURL);
  });
});

源代码：

60214679
    ✓ should pass (2010ms)


  1 passing (2s)

---------------|---------|----------|---------|---------|-------------------
File           | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
---------------|---------|----------|---------|---------|-------------------
All files      |      70 |      100 |      40 |      70 |                   
 index.js      |     100 |      100 |     100 |     100 |                   
 urlBuilder.js |      25 |      100 |       0 |      25 | 3,6,9             
---------------|---------|----------|---------|---------|-------------------