Jasmine matcher 'toHaveEqualContent' - expect two files to have the same content

jasmine-matcher-toHaveEqualContent.js

var fs = require('fs');

var fsp = {
	stat: function(file) {
		return new Promise(function(resolve, reject) {
			fs.stat(file, function(err, stats) {
				if (err) return reject(err);
				return resolve(stats);
			});
		});
	},
	readFile: function(file, options) {
		options = options || {};
		return new Promise(function(resolve, reject) {
			fs.readFile(file, options, function(err, content) {
				if (err) return reject(err);
				return resolve(content);
			});
		});
	}
};

beforeEach(function() {
	jasmine.addMatchers({
		toHaveEqualContent:	function() {
			return {
				compare: function(actual, expected) {
					var result = {};

					var actualContent;
					var expectedContent;

					return fsp.stat(actual)
						.then(function() {
							return fsp.stat(expected);
						})
						.then(function() {
							return fsp.readFile(actual);
						})
						.then(function(content) {
							actualContent = content;
							return fsp.readFile(expected);
						})
						.then(function(content) {
							expectedContent = content;
							result.pass = actualContent === expectedContent;
							return result;
						})
						.catch(function(err) {
							result.message = 'There was an error while trying to compare the files. ' +
								'Maybe some of them does not exist or could not be read.\n' + err.toString();
							return result;
						});
				}
			};
		}
	});
});