3

Why does the following code fail with a timeout? It looks like 'should' throws an error and done() never gets called? How do I write this test so that it fails correctly instead of having jasmine reporting a timeout?

var Promise = require('bluebird');
var should = require('chai').should();
describe('test', function () {
  it('should work', function (done) {
    Promise.resolve(3)
      .then(function (num) {
        num.should.equal(4);
        done();
      });
  });
});

console output is:

c:>jasmine-node spec\

Unhandled rejection AssertionError: expected 3 to equal 4 ... Failures: 1) test should work Message: timeout: timed out after 5000 msec waiting for spec to complete

user3409889
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2 Answers2

5

Using .then() and only done()

it('should work', (done) => {
  Promise.resolve(3).then((num) => {
    // your assertions here
  }).catch((err) => {
    expect(err).toBeFalsy();
  }).then(done);
});

Using .then() and done.fail()

it('should work', (done) => {
  Promise.resolve(3).then((num) => {
    // your assertions here
  }).then(done).catch(done.fail);
});

Using Bluebird coroutines

it('should work', (done) => {
  Promise.coroutine(function *g() {
    let num = yield Promise.resolve(3);
    // your assertions here
  })().then(done).catch(done.fail);
});

Using async/await

it('should work', async (done) => {
  try {
    let num = await Promise.resolve(3);
    // your assertions here
    done();
  } catch (err) {
    done.fail(err);
  }
});

Using async/await with .catch()

it('should work', (done) => {
  (async () => {
    let num = await Promise.resolve(3);
    // your assertions here
    done();
  })().catch(done.fail);
});

Other options

You specifically asked about jasmine-node so that's what the above examples are about but there are also other modules that let you directly return promises from tests instead of calling done() and done.fail() - see:

rsp
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2

If you want to use Promises in your Mocha suite, you have to return it instead of using the done() callback, like:

describe('test', function () {
  it('should work', function () {
    return Promise.resolve(3)
      .then(function (num) {
        num.should.equal(4);
      });
  });
});

An even cleaner way to write that would be with chai-as-promised module:

describe('test', function () {
  it('should work', function () {
    return Promise.resolve(3).should.eventually.equal(4);
  });
});

Just make sure to require it properly and tell chai to use it:

var Promise = require('bluebird');
var chai = require('chai');
var should = chai.should();
var chaiAsPromised = require('chai-as-promised');

chai.use(chaiAsPromised);
Rodrigo Medeiros
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    Thanks for the tip to use chai-as-promised. Using jasmine-node, I had to do `return Promise.resolve(3).should.eventually.equal(4).and.notify(done);` – user3409889 Apr 13 '15 at 20:13
  • Oh, sorry, just now I saw that you were talking about `jasmine`, not `mocha`. But yeah, `chai-as-promised` supports `jasmine` too. And other thing: I'm quite sure recent versions of `jasmine` already supports node by default, so you don't need `jasmine-node` unless you don't want to migrate to a newer version. – Rodrigo Medeiros Apr 13 '15 at 20:23