Merge pull request #72 in BUDC/estatico from feature/ESTATICO_69_bett…

…er_image_comparison_for_test to release/github

* commit 'f5b3b2813fc1e34de7cbb59c5c92db637a2ca95e':
  Promises-based test for media:imageversions Added npm promise as a dev dependency.
  New image testing

helpers/tests.js

@@ -3,7 +3,24 @@
 var should = require('should'), // jshint ignore:line
 	glob = require('glob'),
 	path = require('path'),
-	fs = require('fs');
+	fs = require('fs'),
+	Promise = require('promise'),
+	gm = require('gm'),
+
+	stringComparison = function(expectedFilePath, resultFilePath) {
+		// reading files as strings and trimming them - good for non-binary files
+		var expectedFile = fs.readFileSync(expectedFilePath, 'utf8').trim(),
+			resultFile = fs.readFileSync(resultFilePath, 'utf8').trim();
+
+		resultFile.should.equal(expectedFile, expectedFilePath);
+	},
+
+	bufferComparison = function() {
+		var expectedFile = fs.readFileSync(expectedFilePath),
+			resultFile = fs.readFileSync(resultFilePath);
+
+		resultFile.compare(expectedFile).should.equal(0, expectedFilePath);
+	};
 
 module.exports = {
 	compareResultFilesToExpected: function(testCaseFolderName, options) {
@@ -15,20 +32,44 @@ module.exports = {
 		// Compares files from expected folder and the results of gulp task, executed with fixtures as test data
 		expectedResults.forEach(function(expectedFilePath) {
 			var expectedFileName = path.relative(pathPrefix + '/expected/', expectedFilePath),
-				resultFilePath = path.resolve(pathPrefix + '/results/' + expectedFileName),
-				expectedFile,
-				resultFile;
+				resultFilePath = path.resolve(pathPrefix + '/results/' + expectedFileName);
 
 			if (options && options.asBuffer) {
-				expectedFile = fs.readFileSync(expectedFilePath);
-				resultFile = fs.readFileSync(resultFilePath);
-				resultFile.compare(expectedFile).should.equal(0, expectedFilePath);
+				bufferComparison(expectedFilePath, resultFilePath);
 			} else {
-				// reading files as strings and trimming them - good for non-binary files
-				expectedFile = fs.readFileSync(expectedFilePath, 'utf8').trim();
-				resultFile = fs.readFileSync(resultFilePath, 'utf8').trim();
-				resultFile.should.equal(expectedFile, expectedFilePath);
+				stringComparison(expectedFilePath, resultFilePath);
 			}
 		});
+	},
+
+	compareImagesToExpected: function(testCaseFolderName, cb) {
+		var pathPrefix = path.join(__dirname, '/../test/', testCaseFolderName),
+			expectedResults = glob.sync(pathPrefix + '/expected/**/*', {
+				nodir: true
+			});
+
+		console.log('Starting image comparison...');
+
+		Promise.all(expectedResults.map(function(expectedFilePath) {
+			var expectedFileName = path.relative(pathPrefix + '/expected/', expectedFilePath),
+				resultFilePath = path.resolve(pathPrefix + '/results/' + expectedFileName);
+
+			return new Promise(function(resolve, reject) {
+				gm.compare(expectedFilePath, resultFilePath, 0.01, function(error, equal) {
+					if (equal) {
+						resolve();
+					} else {
+						reject(expectedFileName + ': differs from expected.');
+					}
+				});
+			});
+		})).then(function(message) {
+			console.log('All images are equal.');
+			cb();
+		},
+
+		function(error) {
+			cb(new Error(error));
+		});
 	}
 };