'use strict';

const browserify = require('browserify');
const gulp = require('gulp');
const source = require('vinyl-source-stream');
const buffer = require('vinyl-buffer');
const uglify = require('gulp-uglify-es').default;
const sourcemaps = require('gulp-sourcemaps');
const gutil = require('gulp-util');
const rename = require('gulp-rename');

gulp.task('bundleES', function () {
  // set up the browserify instance on a task basis
  const b = browserify({
    'debug': true,
    'entries': './src/es2016/js/app.js'
  });

  return b.bundle()
    .pipe(source('app.js'))
    .pipe(buffer())
    .pipe(rename('bundle.js'))

    .pipe(sourcemaps.init({ 'loadMaps': true }))
  // Add transformation tasks to the pipeline here.
    .pipe(uglify())
    .on('error', gutil.log)
    .pipe(sourcemaps.write('.'))
    .pipe(gulp.dest('./src/es2016'));
});

gulp.task('buildES', ['bundleES'], function() {
  gulp.watch('src/es2016/js/**/*.js', ['bundleES']);
});