gulpfile.js

var gulp = require("gulp");
var plugins = require("gulp-load-plugins")();
var browserSync = require("browser-sync").create();
//const autoprefixer = require('gulp-autoprefixer');

// Config Object.
var config = {
  assetsDir: "./src",
  sassPattern: "scss/*.scss",
  production: !!plugins.util.env.production,
  sourceMaps: !plugins.util.env.production
};

var app = {};

app.addStyle = function(paths, outputFilename) {
  gulp
    .src(paths)
    .pipe(plugins.plumber())
    .pipe(plugins.if(config.sourceMaps, plugins.sourcemaps.init()))
    .pipe(plugins.sass())
    .pipe(plugins.concat(outputFilename))
    .pipe(plugins.cleanCss())
    .pipe(plugins.if(config.sourceMaps, plugins.sourcemaps.write(".")))
    .pipe(gulp.dest("dist/css"));
};

app.addScript = function(paths, outputFilename) {
  gulp
    .src(paths)
    .pipe(plugins.plumber())
    .pipe(plugins.if(config.sourceMaps, plugins.sourcemaps.init()))
    .pipe(plugins.concat(outputFilename))
    .pipe(plugins.uglify())
    .pipe(plugins.if(config.sourceMaps, plugins.sourcemaps.write(".")))
    .pipe(gulp.dest("dist/js"));
};

// Copy method.
app.copy = function(srcFiles, outputDir) {
  gulp.src(srcFiles).pipe(gulp.dest(outputDir));
};

// Sass styles task. Not used yet.
gulp.task("styles", function() {
  return app.addStyle(
    [
      "./node_modules/bootstrap/dist/css/bootstrap.min.css",
      config.assetsDir + "/scss/**/*.scss",
      "./node_modules/font-awesome/css/font-awesome.min.css"
    ],
    "style.min.css"
  );
});

// Scripts task.
gulp.task("scripts", function() {
  return app.addScript(
    [
      "./node_modules/js-polyfills/polyfill.min.js",
      "./node_modules/jquery/dist/jquery.min.js",
      "./node_modules/bootstrap/dist/js/bootstrap.min.js",
      "./node_modules/wowjs/dist/wow.min.js",
      "./node_modules/jquery-visible/jquery.visible.min.js",
      "./node_modules/fittext.js/jquery.fittext.js",
      "./src/js/jsquery.easing.min.js",
      config.assetsDir + "/js/**/*.js"
    ],
    "scripts.min.js"
  );
});

// Task for fonts
gulp.task("html", function() {
  return app.copy("./src/*.html", ".");
});

// Task for fonts
gulp.task("fonts", function() {
  return app.copy("./node_modules/font-awesome/fonts/**", "dist/fonts");
});

// Images optimization.
gulp.task("images", function() {
  gulp
    .src(config.assetsDir + "/img/**")
    .pipe(plugins.imagemin())
    .pipe(gulp.dest("dist/img"));
});

gulp.task("favicons", function() {
  gulp.src(config.assetsDir + "/favicons/**").pipe(gulp.dest("dist/favicons"));
});

// Static server
gulp.task("browser-sync", function() {
  !config.production
    ? browserSync.init({
        server: {
          baseDir: "./"
        }
      })
    : plugins.util.noop();
});

// Watch task. Watches for changes.
gulp.task("watch", function() {
  if (!config.production) {
    gulp.watch(config.assetsDir + "/" + config.sassPattern, ["styles"]);
    gulp.watch(config.assetsDir + "/js/**/*.js", ["scripts"]);
    gulp.watch("*.html").on("change", browserSync.reload);
  }
});

// Defautl task.
gulp.task("default", [
  "html",
  "styles",
  "scripts",
  "images",
  "favicons",
  "fonts",
  "browser-sync",
  "watch"
]);