gulpfile.js

/*eslint no-console: ["error", { allow: ["log", "warn", "error"] }] */
'use strict';

const gulp = require('gulp');
const debug = require('gulp-debug');
const del = require('del');
const sass = require('gulp-sass');
const sourcemaps = require('gulp-sourcemaps');
const concat = require('gulp-concat');
const postcss = require('gulp-postcss');
const autoprefixer = require('autoprefixer');
const babel = require('gulp-babel');
const rev = require('gulp-rev');

const paths = {
  dist: './dist',
  styles: [
    /* Paths to your styles go here */
  ],
  scripts: [
    /* Paths to your scripts go here */
  ]
};

function styles() {
  return gulp.src(paths.styles)
    .pipe(debug({ title : 'Styles:' }))
    .pipe(sourcemaps.init())
    .pipe(sass().on('error', function (err) {
          console.error('error', err.message);
          this.emit('end');
     }))
    .pipe(concat('styles.all.css'))
    .pipe(postcss([
      autoprefixer({})
    ]))
    .pipe(sourcemaps.write('./'))
    .pipe(gulp.dest(paths.dist + '/styles'))
}

function scripts() {
  return gulp.src(paths.scripts)
    .pipe(debug({ title : 'Scripts:' }))
    .pipe(sourcemaps.init())    
    .pipe(babel({
      presets: ['es2015'],
    }))
    .pipe(concat('scripts.all.js'))
    .pipe(sourcemaps.write('./'))
    .pipe(gulp.dest(paths.dist + '/scripts'));
}

function revision() {
  return gulp.src([
    paths.dist + '/**/*.css',
    paths.dist + '/**/*.js'
  ])
  .pipe(debug({ title : 'Manifest:' }))
  .pipe(sourcemaps.init())
  .pipe(rev())
  .pipe(sourcemaps.write('.'))
  .pipe(gulp.dest(paths.dist))
  .pipe(rev.manifest())
  .pipe(gulp.dest(paths.dist));
}

function clean() {
  return del([ paths.dist ]);
}

const build = gulp.series(clean, gulp.parallel(styles, scripts), revision);

clean.description = 'Clean\'s everything up neat and tidy';
build.description = 'Build the entire site';

exports.clean = clean;
exports.build = build;

gulp.task('default', build);