javascript - 当 promise 在断言期间被拒绝时，业力通过测试

Question

如果 promise 本身在 'does fail' 测试中被拒绝，那么测试将如我所料失败。如果断言失败/抛出错误/ promise 在 promise 的“then”中被拒绝，我会记录说 ERROR: 'Unhandled promise rejection' 并且测试仍然通过。我如何让它在拒绝时失败而不是记录拒绝未处理？

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

Answer 1

您必须返回 then(...) 的返回值，而不是您创建的第一个 promise。