在测试promise rejections时，当使用带有chai-as-promised的Mocha时，获取“不是一种可能”

Question

提前感谢您在这方面的帮助！

艰难地使用Mocha、Chai和Chai测试promise rejections正如我承诺的那样我试图使用async/await来实现这一点，但无法成功，我决定从基础开始。

我希望test 3至少能通过摩卡测试。我做错了什么？

我使用了以下代码：

const chai = require('chai');
const chaiAsPromised = require("chai-as-promised")

chai.use(chaiAsPromised)
const should = chai.should()

describe.only('Testing promise tests', () => {
  const errortest = () => Promise.reject('rejecting...')
  it('test 1', () => {
    Promise.reject('rejecting...').should.throw();
  });
  it('test 2', () => {
    errortest.should.throw();
  });
  it('test 3', () => {
    errortest.should.eventually.throw();
  });
});

我的控制台输出：

 0 passing (10ms)
  3 failing

  1) Testing promise tests
       test 1:
     AssertionError: expected {} to be a function
      at Context.<anonymous> (test/promise.test.js:17:42)
      at processImmediate (internal/timers.js:456:21)

  2) Testing promise tests
       test 2:
     AssertionError: expected [Function: errortest] to throw an error
      at Context.<anonymous> (test/promise.test.js:22:27)
      at processImmediate (internal/timers.js:456:21)

  3) Testing promise tests
       test 3:
     TypeError: [Function: errortest] is not a thenable.
      at assertIsAboutPromise (node_modules/chai-as-promised/lib/chai-as-promised.js:31:19)
      at Assertion.<anonymous> (node_modules/chai-as-promised/lib/chai-as-promised.js:53:13)
      at Assertion.propertyGetter (node_modules/chai/lib/chai/utils/addProperty.js:62:29)
      at Object.get (<anonymous>)
      at Object.proxyGetter [as get] (node_modules/chai/lib/chai/utils/proxify.js:98:22)
      at Context.<anonymous> (test/promise.test.js:26:22)
      at processImmediate (internal/timers.js:456:21)

Answer 1

您需要调用errortest。现在你只需要使用function对象，这样做.should.eventually.throw()就没有任何意义了。对象不会引发；只有代码执行才能引发。

因此，添加括号：errortest().should.eventually.throw()