gulpfile.js

const $ = require('gulp');
const $bro = require('gulp-bro');
const $changed = require('gulp-changed');
const $concat = require('gulp-concat');
const $htmlmin = require('gulp-htmlmin');
const $plumber = require('gulp-plumber');
const $postcss = require('gulp-postcss');
const $sourcemap = require('gulp-sourcemaps');
const $terser = require('gulp-terser');

const merge2 = require('merge2');
const browserify = require('browserify');
const babelify = require('babelify');
const del = require('del');
const server = require('browser-sync').create();

$.task('build', $.series(clean, $.parallel(pages, styles, assets, scripts)));
$.task('default', $.series('build', $.parallel(serve, watch)));
$.task('publish', publish);

function clean() {
  return del(['build']);
}

function reload(done) {
  server.reload();
  done();
}

function watch() {
  $.watch('docs_src/index.html', $.series(pages, reload));
  $.watch('docs_src/css/*.css', $.series(styles, reload));
  $.watch('docs_src/models/*', $.series(assets, reload));
  $.watch('docs_src/js/*', $.series(scripts, reload));
}

function serve(done) {
  server.init({server: 'build'});
  done();
}

function pages() {
  return $.src(['docs_src/index.html'])
    .pipe($changed('build'))
    .pipe($plumber())
    .pipe($htmlmin({
      removeComments: true,
      collapseWhitespace: true,
      removeEmptyAttributes: true,
      minifyJS: true,
      minifyCSS: true}))
    .pipe($.dest('build'));
}

function styles() {
  return $.src('docs_src/css/*.css')
    .pipe($changed('build'))
    .pipe($plumber())
    .pipe($postcss([
      require('precss'),
      require('cssnano')({
        autoprefixer: {browsers: ['last 2 version'], add: true},
        discardComments: {removeAll: true}})]))
    .pipe($.dest('build/css'));
}

function assets() {
  var s0 = $.src('docs_src/models/*')
      .pipe($changed('build'))
      .pipe($.dest('build/models'));
  var s1 = $.src('docs_src/img/*')
      .pipe($changed('build'))
      .pipe($.dest('build/img'));
  return merge2(s0, s1);
}

function scripts() {
  return $.src(['docs_src/js/jquery.min.js',
                'docs_src/js/three.min.js',
                'docs_src/js/TrackballControls.js',
                'docs_src/js/MTLLoader.js',
                'docs_src/js/LoaderSupport.js',
                'docs_src/js/OBJLoader2.js',
                'docs_src/js/tf.min.js',
                'docs_src/js/mobilenet.js',
                'docs_src/js/app.js',])
    .pipe($.dest('./build/js'));
}

function publish() {
  return $.src('./build/**/*').pipe($.dest('./docs'));
}