gulpfile.js

var SRC_JS        = 'client/js/**/*.js';
var SRC_LESS      = 'client/less/**/styles.less';
var SRC_HTML      = '*.html';
var DEST_STYLES   = 'static/styles/';
var DEST_SCRIPTS  = 'static/scripts/';
var PROXY         = 'localhost:8000';

var gulp          = require('gulp');
var gutil         = require('gulp-util');
var jshint        = require('gulp-jshint');
var less          = require('gulp-less');
var sourcemaps    = require('gulp-sourcemaps');
var uglify        = require('gulp-uglify');
var concat        = require('gulp-concat');
var rename        = require('gulp-rename');
var cssmin        = require('gulp-cssmin');
var del           = require('del');
var browserSync   = require('browser-sync').create();

gulp.task('default', ['watch']);

gulp.task('clean', function() {
   del([
      DEST_SCRIPTS,
      DEST_STYLES
   ]);
});

gulp.task('build', ['css', 'js']);

gulp.task('lint', function() {
   return gulp.src(SRC_JS)
      .pipe(jshint())
      .pipe(jshint.reporter('jshint-stylish'))
      .pipe(jshint.reporter('fail'));
});

gulp.task('js', ['lint'], function() {
   return gulp.src(SRC_JS)
      .pipe(sourcemaps.init())
      .pipe(concat('bundle.js'))
      .pipe(uglify())
      .pipe(rename({suffix: '.min'}))
      .pipe(sourcemaps.write('.'))
      .pipe(gulp.dest(DEST_SCRIPTS));
});

gulp.task('css', function() {
   return gulp.src(SRC_LESS)
      .pipe(sourcemaps.init())
      .pipe(less())
      .pipe(cssmin())
      .pipe(rename({suffix: '.min'}))
      .pipe(sourcemaps.write('.'))
      .pipe(gulp.dest(DEST_STYLES))
      .pipe(browserSync.stream({match: '**/*.css'}));
});

gulp.task('watch', function() {
   browserSync.init({
      open: false,
      notify: false,
      proxy: PROXY
   });

   gulp.watch(SRC_JS, ['js']);
   gulp.watch(SRC_LESS, ['css']);
   gulp.watch(SRC_HTML, browserSync.reload);
});