gulpfile

// Load Gulp and Plugins
var gulp = require('gulp'),
    browserSync = require('browser-sync').create(),
    $ = require('gulp-load-plugins')({ lazy: true });

// Paths
var path = {
    lessWatch:  'assets/less/**/*.less',
    lessSrc:    'assets/less/sites/*.less',
    cssDest:    'assets/css/sites/',
    csHtml:     'views/**/*.cshtml'
};

// Less
var LessPluginCleanCSS = require("less-plugin-clean-css"),
    cleancss = new LessPluginCleanCSS({ advanced: false });
var LessPluginAutoPrefix = require('less-plugin-autoprefix'),
    autoprefix = new LessPluginAutoPrefix({ browsers: ["last 2 versions"] });

gulp.task('less', function () {
    console.log("in less task");
    gulp.src(path.lessSrc)
      .pipe($.plumber())
      .pipe($.debug())
      .pipe($.changed(path.cssDest, { extension: '.css' }))
      .pipe($.bytediff.stop(function (data) {
          var difference = (data.savings > 0) ? ' smaller.' : ' larger.';
          return data.fileName + ' is ' + data.percent.toFixed(2) + '%' + difference;
      }))
      .pipe(gulp.dest(path.cssDest))
      .pipe(browserSync.stream());
});

// Browser Sync
gulp.task('browserSync', function () {
    browserSync.init({
        port: 8080,
        files: [path.cssDest, path.csHtml]
    });
});

// Default
gulp.task('default', ['less', 'watch', 'browserSync']);

// Watch
gulp.task('watch', function () {
    gulp.watch(path.lessWatch, { interval: 500 }, ['less']); // set interval above default 100ms to prevent CPU spiking over 50%
    gulp.watch(path.csHtml).on('change', browserSync.reload);
});