Simple gulpfile for WP theme

gulpfile.js

/* ==========================================================================
   Dependencies   
   ========================================================================== */
   
var gulp = require('gulp'),
    clean = require('gulp-clean'),
    uglify = require('gulp-uglify'),
    autoprefixer = require('gulp-autoprefixer'),
    concat = require('gulp-concat'),
    rename = require('gulp-rename'),
    sass = require('gulp-sass'),
    notify = require("gulp-notify"),
    cache = require('gulp-cache'),
    imagemin = require('gulp-imagemin'),
    plumber = require('gulp-plumber');

/* ==========================================================================
   Sources - Set your folders here
   ========================================================================== */

var source = {
  // Javascript folder
  js_src: "./js",
  // Javascript Library folder
  js_libs: "./js/lib/",
  // Sass folder
  sass_src: "./sass",
  //CSS output folder
  css_src: "./"
};

/* ==========================================================================
   Sass watch task
   Watches and compiles sass files in sass directory, also applies autoprefier
   ========================================================================== */

gulp.task('sass', function(){
  // return gulp.src('./sass/*.scss')
  return gulp.src(source.sass_src+'/*.scss')

    .pipe(plumber({errorHandler: notify.onError("Ack. <%= error.message %>")}))
    .pipe(sass({
      outputStyle: 'compressed',
      noCache: true
    })
    .on('error', sass.logError))
    .pipe(autoprefixer('last 100 versions'))
    .pipe(gulp.dest(source.css_src));
});


/* ==========================================================================
   gulp scripts
   Concatenates and minifies javascript files excluding modernizr
   and IE6-8 specific selectivizr.js
   ========================================================================== */

// Your javascript vendor/library files to be concatenated and minified
gulp.task('scripts', ['cleanScripts'], function() {
  return gulp.src([source.js_libs+'/*.js', '!'+source.js_libs+'modernizr.js', '!'+source.js_libs+'selectivizr.js'])
    .pipe(concat("plugins.js"))
    .pipe(gulp.dest(source.js_src))
    .pipe(rename({suffix: '.min'}))
    .pipe(uglify())
    .pipe(gulp.dest(source.js_src))
    .pipe(notify({message: 'Scripts are done.'}));
});

// Clean plugins.min.js file
gulp.task('cleanScripts', function() {
  return gulp.src('./js/plugins.min.js', {read: false})
    .pipe(clean());
});

/* ==========================================================================
   gulp images
   Minifies images
   ========================================================================== */

gulp.task('images', function() {
  gulp.src('./images/**')
    .pipe(cache(imagemin({
      optimizationLevel: 5,
      progressive: true,
      interlaced: true
    })))
    .pipe(gulp.dest('./images/'))
    .pipe(notify({
      message: "Images are optimized."
  }));
});

/* ==========================================================================
   gulp watch
   Main gulp task to watch sass files for changes
   ========================================================================== */

gulp.task('watch', function () {

    // Watch .scss files
    gulp.watch(source.sass_src+'/**/*.scss', ['sass']);

    // Watch all files for changes
    gulp.watch(['./*', '!./*.css']);

});

/* ==========================================================================
   default task
   ========================================================================== */

gulp.task('default', function(){
  gulp.start('watch', 'scripts', 'images');
});