Example usage 4 uglify

gulpfile.js

// Include gulp
var gulp = require('gulp'); 

// Include Our Plugins
var jshint = require('gulp-jshint');
var concat = require('gulp-concat');
var uglify = require('gulp-uglify');
var rename = require('gulp-rename');
var clean = require('gulp-clean');
var sourcemaps = require('gulp-sourcemaps');
var ngAnnotate = require('gulp-ng-annotate');
var sass = require('gulp-sass');

var jsFiles = [
    'front/js/modules/**/*.js'    
];
var sassFiles = [
    'front/sass/*.*'      
];

gulp.task('clean', function() {
    return gulp.src(['front/js/all.js'], {read: false})
        .pipe(clean({force: true}));
});

gulp.task('lint', function() {
    return gulp.src(jsFiles)
        .pipe(jshint())
        .pipe(jshint.reporter('default'));
});

gulp.task('minify', ['lint'], function() {
    return gulp.src(jsFiles)
        .pipe(sourcemaps.init())
        .pipe(ngAnnotate({single_quotes:true,add:true}))
        .pipe(uglify())
        .pipe(concat('all.min.js'))
        .pipe(gulp.dest('front/js'));
});

gulp.task('sass', function () {
  gulp.src(sassFiles)
    .pipe(sass.sync().on('error', sass.logError))
    .pipe(gulp.dest('front/css'));
});

gulp.task('watch',function(){
    gulp.watch(jsFiles,['minify']);
    gulp.watch(sassFiles,['sass']);
})
// Default Task
gulp.task('default', ['minify']);