在测试 promise 拒绝时，在将 Mocha 与 chai-as-promised 一起使用时获得“不是一个 thenable”

Question

Thanks in advance for any assistance on this!

Struggling testing promise rejections using Mocha, Chai, and Chai as Promised I tried to accomplish this with async/await, but was unable to succeed, I decided to go to basics.

I expected at LEAST test 3 to pass the mocha test. What am I doing wrong?

I'm using the following code:

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();
  });
});

My console output:

 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

You need to invoke errortest . Right now you just use the function object, and then it makes no sense to do .should.eventually.throw() . An object does not throw; only code execution can.

So, add parentheses: errortest().should.eventually.throw()