mock-server.js

(function() {
	/** 
	 * Return a Promise that resolves with the specified value, after the specified timeout.
	 * @param {Any} resolveWithValue Value with which to resolve Promise.
	 * @param {Integer} timeout Number of milliseconds after which to resolve Promise
	 * @returns {Promise}
	*/
	function delay(resolveWithValue, timeout) {
		return new Promise((resolve, reject) => {
			setTimeout(() => {
				resolve(resolveWithValue);
			}, timeout);
		});
	}

	var mock = XHRMock;

	mock.setup();
	
	mock.get('story', (req, res) => {
		var response = res.status(200).body(JSON.stringify({
			title: 'My Story',
			chapters: ['chapter1', 'chapter2', 'chapter3', 'chapter4']
		}));

		return delay(response, Math.random() * 5000);
	});

	var chapters = {
		chapter1: '1. Humpty Dumpty sat on a wall,',
		chapter2: '2. Humpty Dumpty had a great fall;',
		chapter3: '3. All the king\'s horses and all the king\'s men',
		chapter4: '4. Couldn\'t put Humpty together again.' 
	};

	mock.get(/^chapter/, (req, res) => {
		var query = req.url().query;
		
		var id = query && query.id;

		var text = chapters[id];

		var response = res.status(200).body(JSON.stringify({
			id,
			text
		}));

		return delay(response, Math.random() * 5000);
	});
})();