intern-promises.js

define([
	'intern!object',
	'intern/chai!expect',
	'sinon',
	'when',
	'intern/chai!',
	'sinon-chai'
], function (registerSuite, expect, sinon, promise, chai, sinonChai) {
	// add sinon assertions to chai
	chai.use(sinonChai);

	function promiseThatResolves() {
		return promise.promise(function(resolve, reject) { reject(42); });
	}
	function promiseThatRejects() {
		return promise.promise(function(_, reject) { reject('A rejected promise'); });
	}
	function functionThatCallsMockedDependency(externalDependency) {
		return promise.promise(function(resolve) {
			externalDependency.method();
			resolve();
		});
	}

	registerSuite({
		name: 'promises and intern',

		'resolving promises': function () {
			// This will implicitly handle the case where the promise rejects
			return promiseThatResolves().then(function (value) {
				// If the expectation isn't met, it throws and the promise
				// rejects, which fails the test
				expect(value).to.equal(42);
			});
		},

		'a rejected promise example': function () {
			return promiseThatRejects().then(
				function () {
					throw new Error('should not have resolved');
				},
				function (value) {
					expect(value).to.equal('A rejected promise');
				}
			);
		},

		'testing for a mock-call': function () {
			var dfd = this.async(),
				myMock = { method: sinon.spy() };

			functionThatCallsMockedDependency(myMock).then(
				// dfd.callback returns a function that executes the callback passed
				// like so:
				// try { callback(value); dfd.resolve(); }
				// catch(e) { dfd.reject(e); }
				dfd.callback(function (value) {
					expect(myMock.method).to.have.been.called;
				}),
				dfd.reject
			);
		}
	});
});