断言期间诺言被拒绝时,业力通过测试

如果诺言本身像“确实失败”测试中那样被拒绝,那么测试就会失败,正如我所期望的那样.如果断言失败/抛出错误/在promise的“ then”中拒绝了promise,我会记录错误：“未处理的promise拒绝”,并且测试仍然通过.如何使它在拒绝时失败,而不是记录未处理的拒绝？

import { expect } from 'chai';

describe.only('What?', () => {
  const e = new Error('NOPE');

  it('does fail', () => Promise.reject(e));

  it('should fail when rejected', () => {
    const promise = new Promise(r => r());

    promise.then(() => Promise.reject(e));

    return promise;
  });

  it('should fail when thrown, then caught then rejected', () => {
    const promise = new Promise(r => r());

    promise
      .then(() => { throw e; })
      .catch(() => Promise.reject('huh'));

    return promise;
  });

  it('should fail/reject when thrown, then caught then rethrown', () => {
    const promise = new Promise(r => r());

    promise
      .then(() => { throw e; })
      .catch(er => { throw er; });

    return promise;
  });

  it(`doesn't matter if I expect`, () => {
    const promise = new Promise(r => r());

    promise.then(() => {
      expect(1).to.eq(2);
    });

    return promise;
  });
});

然后报告…

START:
  What?
    ✖ does fail
    ✔ should fail when rejected
ERROR: 'Unhandled promise rejection', Error{stack: undefined}
    ✔ should fail when thrown, then caught then rejected
ERROR: 'Unhandled promise rejection', 'huh'
    ✔ should fail/reject when thrown, then caught then rethrown
ERROR: 'Unhandled promise rejection', Error{stack: undefined, line: 47567, sourceURL: 'http://localhost:9876/base/test/test_index.js?7f696b0b50c0a51c7a2fa5278582072b20241a3b'}
    ✔ doesn't matter if I expect
ERROR: 'Unhandled promise rejection', AssertionError{message: 'expected 1 to equal 2', showDiff: true, actual: 1, expected: 2, stack: 'AssertionError@http://localhost:9876/base/test/test_index.js?7f696b0b50c0a51c7a2fa5278582072b20241a3b:39222:25

解决方法:

您必须返回then(…)的返回值,而不是您创建的第一个承诺.

标签：promise,karma-mocha,javascript
来源： https://codeday.me/bug/20191118/2026583.html