javascript - Chai-as-promised - 带有 promise 的期望总是转换成一个空对象

Question

来自 chai-as-promised 的文档

(2 + 2).should.equal(4);

// becomes
return Promise.resolve(2 + 2).should.eventually.equal(4);

expect({ foo: "bar" }).to.have.property("foo");

// becomes
return expect(Promise.resolve({ foo: "bar" })).to.eventually.have.property("foo");

但如果我尝试

import chai from 'chai';
import sinon from 'sinon';
import sinonChai from 'sinon-chai';
import dirtyChai from 'dirty-chai';
import chaiAsPromised from 'chai-as-promised';

chai.use(sinonChai);
chai.use(dirtyChai);
chai.use(chaiAsPromised);

//...

it.only('test', function() {
   return expect(Promise.resolve({ foo: 'bar' })).to.eventually.have.property('foo');
});

我得到了这个断言错误：

AssertionError: expected {} to have a property 'foo'

我用不同的用例和断言尝试了它，但它总是一样的，从中出来expect(promise)的总是一个空对象。

知道为什么吗？

我用

"chai-as-promised": "6.0.0",
"chai": "^3.5.0",
"dirty-chai": "^1.2.2",
"mocha": "3.2.0",
"sinon": "^1.17.3",
"sinon-chai": "^2.8.0"

Answer 1

应该可以工作，正如@LostJon 提到的，您没有展示如何导入 chai 库。
例如

let chai = require("chai");
let chaiAsPromised = require("chai-as-promised");

chai.use(chaiAsPromised);
let expect = chai.expect;

describe('chai as promise', () => {
    it('some async test', () => {        

        return expect(Promise.resolve({foo:'bar'})).to.eventually.have.property("foo");

    });
});

该示例适用于以下内容：

"dependencies": {
    "chai": "^3.5.0",
    "chai-as-promised": "^6.0.0",
    "mocha": "^3.2.0"
  }