gulp

gulpfile.js

var gulp = require('gulp');

var concat = require('gulp-concat');
var uglify = require('gulp-uglify');
var imagemin = require('gulp-imagemin');
var minifyCSS = require('gulp-minify-css');
var autoprefixer = require('gulp-autoprefixer');
var sourcemaps   = require('gulp-sourcemaps');
var please = require('gulp-pleeease');
var rename = require('gulp-rename');

var paths = {
    css: 'static/css/min/**/*',
    images: 'static/img/min/**/*',
    scripts: 'static/js/min/**/*.js'
};


gulp.task('scripts', function () {
    // Minify and copy all JavaScript (except vendor scripts)
    return gulp.src(paths.scripts)
        .pipe( uglify({ preserveComments: 'none' }))
        .pipe( concat('libs.min.js') )
        .pipe( gulp.dest('static/js') );
});


gulp.task('css', function() {
    gulp.src('static/css/style.css')
        .pipe(sourcemaps.init())
        .pipe(please({
            mqpacker: true,
            autoprefixer: {browsers: ['last 4 versions']}
        }))
        .pipe(rename({
          suffix: '.min',
          extname: '.css'
        }))
        .pipe(sourcemaps.write('./', {
            sourceMappingURLPrefix: '/static/css/'
        }))
        .pipe(gulp.dest('static/css'));
});


 // Copy all static images
 gulp.task('images', function() {
 return gulp.src(paths.images)
     .pipe(imagemin({optimizationLevel: 5}))
     .pipe(gulp.dest('static/img'));
 });

// Rerun the task when a file changes
gulp.task('watch', function () {
    gulp.watch(paths.scripts, ['scripts']);
    gulp.watch(paths.images, ['images']);
    gulp.watch(paths.css, ['css']);
    gulp.watch('static/css/style.css', ['css']);
});

// The default task (called when you run `gulp` from cli)
gulp.task('default', ['watch', 'scripts', 'images', 'css']);