Jasmine Promise Matchers

Custom matchers for testing ES6 Promises with Jasmine 2.x.

This library is compatible with the ES6Promise polyfill library if the current browser does not support ES6 Promises. (This means it will work with Phantom JS.)

Installing

You can install with either NPM or Bower like so:

npm install jasmine-es6-promise-matchers
bower install jasmine-es6-promise-matchers

Overview

Testing promises should be simple, but it's normally a bit of a hassle. Your tests probably look something like this:

var resolvedValue;

promise.then(
  function(value) {
    resolvedValue = value;
  });

jasmine.clock().tick(1);

expect(resolvedValue).toBe('something');

Using the matchers provided by this library, your tests could instead look like this:

expect(promise).toBeResolvedWith('something');

Initializing the library

To use it, just install the library before your tests begin:

beforeEach(function() {
  // `true` automatically ticks the Jasmine mock-clock for you after each assert.
  // `false` leaves the clock management up to you.
  // I recommend `true` unless your test involves other timing concerns.
  JasminePromisMatchers.install(true);
});

And uninstall it once your tests are over:

afterEach(function() {
  JasminePromisMatchers.uninstall();
});

Now you're ready to start testing!

Using the matchers

This library includes a couple of matchers, shown below.

toBeRejected

Verify that a Promise is rejected!

expect(promise).toBeRejected();

toBeRejectedWith

Verify that a Promise is rejected with a specific value:

expect(promise).toBeRejectedWith('something');

toBeResolved

Verify that a Promise is resolved!

expect(promise).toBeResolved();

toBeResolvedWith

Verify that a Promise is resolved with a specific value:

expect(promise).toBeResolvedWith('something');

Questions? Suggestions?

Open an issue or toss up a pull request if you'd like to see anything added to this library!