UI-3211: Handle and display error object on uglification error (#219)

gulp/tasks/javascript.js

@@ -6,13 +6,13 @@ var paths = require('../paths.js');
 
 gulp.task('minify-js', function() {
 	return gulp.src([paths.tmp + '/js/main.js', paths.tmp + '/js/templates.js'])
-		.pipe(uglify())
+		.pipe(uglify().on('error', handleUglifyError))
 		.pipe(gulp.dest(paths.tmp + '/js/'));
 });
 
 gulp.task('minify-js-app', function() {
 	return gulp.src(paths.app + 'app.js')
-			.pipe(uglify())
+			.pipe(uglify().on('error', handleUglifyError))
 			.pipe(gulp.dest(paths.app));
 });
 
@@ -22,4 +22,8 @@ gulp.task('lint', function() {
 	return gulp.src(pathToLint)
 				.pipe(eslint())
 				.pipe(eslint.format());
-});
+});
+
+function handleUglifyError(error) {
+	console.error(JSON.stringify(error, null, 4));
+}