有没有一个函数可以测试在js中有回调的对象实例？

Question

我正在使用sinon来存根一个对象的实例，该对象的实例在一个带有回调的函数中，我该如何测试它呢？我不知道如何测试它，这抛出了一个错误。

这是将js与sinon和mocha一起使用。

该函数为：

import tracker from 'pivotaltracker';

export async function getPivotalProjects(token) {
  const clientTracker = new tracker.Client(token);
  const userProjects = () => new Promise((resolve, reject) => {
    clientTracker.projects.all((error, projects) => (projects ? resolve(projects) : reject(error)));
  });
  return userProjects();

测试结果是：

import tracker from 'pivotaltracker';
let spyTracker;
    beforeEach(() => {
      spyTracker = sinon.stub(tracker, 'Client');
    });

it('should do the request to get the activities from projects.', async () => {
      spyTracker.callsArgWith(1, null, [true, 'token']);
      // spyTracker.projects.all.returns('token');
      await PivotalTrackerApi.getPivotalProjects('token');
      sinon.assert.threw(spyTracker);
spyTracker.restore();
    });

那有什么问题呢？如果有人能帮我，那就太好了。

Answer 1

getPivotalProjects可以简化为：

export async function getPivotalProjects(token) {
  const clientTracker = new tracker.Client(token);
  await new Promise((resolve, reject) => {
    clientTracker.projects.all((error, projects) => (projects ? resolve(projects) : reject(error)));
  });
}

...and可以像这样测试它：

let clientStub;

beforeEach(() => {
  clientStub = sinon.stub(tracker, 'Client');
});

it('should do the request to get the activities from projects.', async () => {
  const allSpy = sinon.spy();
  clientStub.callsFake((token) => ({ projects: { all: allSpy } }));
  const promise = PivotalTrackerApi.getPivotalProjects('token');
  sinon.assert.calledWith(clientStub, 'token');  // Success!
  sinon.assert.called(allSpy);  // Success!
  const callback = allSpy.lastCall.args[0];
  callback(null, 'my projects');
  const result = await promise;
  expect(result).to.equal('my projects');  // Success!
});