gulpfile.js

const gulp       = require('gulp')
const terser     = require('gulp-terser')
const rename     = require('gulp-rename')
const concat     = require('gulp-concat')
const changed    = require('gulp-changed').default
const cleancss   = require('gulp-clean-css')
const eslint     = require("gulp-eslint-new")
const { rimraf } = require('rimraf')
const ejs        = require('ejs')
const fs         = require('fs')

const LIBDIR = 'lib'
const LIBJS  = LIBDIR+"/js"
const LIBCSS = LIBDIR+"/css"
const LIBIMG = LIBDIR+"/images"
const LIBFAV = LIBDIR+"/favicons"
const DOCDIR = './docs' // not currently used

async function clean() {
  await Promise.all([ rimraf(LIBJS),
                      rimraf(LIBCSS),
                      rimraf(LIBIMG),
                      rimraf(LIBFAV) ])
}
gulp.task('clean', function(cb) { clean().then(cb) });

function clean_css() {
  return gulp.src(['src/jsbrain.css',
                   'src/newdesign.css',
                   'src/editorpage.css',
                   'src/pikaday.css']).pipe(changed(LIBCSS))
                                      .pipe(cleancss())
                                      .pipe(gulp.dest(LIBCSS))
}

function compress_js() {
  return gulp.src(['src/polyfit.js',
                   'src/pikaday.js',
                   'src/butil.js',
                   'src/broad.js',
                   'src/beebrain.js',
                   'src/bgraph.js',
                   'src/bsandbox.js',
                   'src/btest.js',
                   'src/client.js',
                   'src/newdesign.js'])
    .pipe(changed(LIBJS, { extension: '.min.js' }))
    .pipe(terser())
    .pipe(rename({ extname: '.min.js' }))
    .pipe(gulp.dest(LIBJS))
}

function combine_bbrjs() {
  return gulp.src(['src/butil.js','src/broad.js','src/beebrain.js'])
    .pipe(concat('bbrpack.js'))
    .pipe(gulp.dest(LIBJS))
}

function combine_bgrjs() {
  return gulp.src(['src/polyfit.js',
                   'src/pikaday.js',
                   'src/butil.js',
                   'src/broad.js',
                   'src/beebrain.js',
                   'src/bgraph.js']).pipe(concat('bgrpack.js'))
                                    .pipe(gulp.dest(LIBJS))
}

function combine_bsbjs() {
  return gulp.src(['src/polyfit.js',
                   'src/pikaday.js',
                   'src/butil.js',
                   'src/broad.js',
                   'src/beebrain.js',
                   'src/bgraph.js',
                   'src/bsandbox.js']).pipe(concat('bsbpack.js'))
                                      .pipe(gulp.dest(LIBJS))
}

function combine_js(cb) {
  let a = gulp.series(combine_bbrjs, combine_bgrjs, combine_bsbjs)
  return a(cb)
}

function combine_bbrjsmin() {
  return gulp.src(['lib/js/butil.min.js',
                   'lib/js/broad.min.js',
                   'lib/js/beebrain.min.js'])
    .pipe(concat('bbrpack.min.js'))
    .pipe(gulp.dest(LIBJS))
}

function combine_bgrjsmin() {
  return gulp.src(['lib/js/polyfit.min.js',
                   'lib/js/pikaday.min.js',
                   'lib/js/butil.min.js',
                   'lib/js/broad.min.js',
                   'lib/js/beebrain.min.js',
                   'lib/js/bgraph.min.js']).pipe(concat('bgrpack.min.js'))
                                           .pipe(gulp.dest(LIBJS))
}

function combine_bsbjsmin() {
  return gulp.src(['lib/js/polyfit.min.js',
                   'lib/js/pikaday.min.js',
                   'lib/js/butil.min.js',
                   'lib/js/broad.min.js',
                   'lib/js/beebrain.min.js',
                   'lib/js/bgraph.min.js',
                   'lib/js/bsandbox.min.js']).pipe(concat('bsbpack.min.js'))
                                             .pipe(gulp.dest(LIBJS))
}

function combine_jsmin(cb) {
  let a = gulp.series(combine_bbrjsmin, combine_bgrjsmin, combine_bsbjsmin)
  return a(cb)
}

function copy_vendor() {
  return gulp.src(['src/moment.min.js', 'src/moment-timezone.min.js'])
    .pipe(gulp.dest(LIBJS))
}

function linter() {
  return gulp.src(['src/butil.js', 'src/broad.js', 'src/bgraph.js', 
                   'src/bsandbox.js', 'src/newdesign.js'])
    .pipe(eslint())
    .pipe(eslint.format())
}

function images () { // Copy images from src to lib
  // Gulp 5: keep the stream in Buffer-mode so PNGs aren't re-encoded as UTF-8
  return gulp.src('src/images/*', { encoding: false }).pipe(gulp.dest(LIBIMG))
}

function favicons () { // Copy favicons from src to lib
  return gulp.src('src/favicons/*', { encoding: false }).pipe(gulp.dest(LIBFAV))
}

function generate_qual_html() {
  // Generate quals/generated/newdesign.html from views/newdesign.ejs
  const ejsTemplate = fs.readFileSync('views/newdesign.ejs', 'utf8')
  const html = ejs.render(ejsTemplate, { user: null })

  // Ensure generated directory exists
  if (!fs.existsSync('quals/generated')) {
    fs.mkdirSync('quals/generated', { recursive: true })
  }

  fs.writeFileSync('quals/generated/newdesign.html', html)
  return Promise.resolve()
}

exports.compile = gulp.series(
  clean,
  gulp.parallel(images, favicons),
  compress_js,
  gulp.parallel(combine_js, combine_jsmin, clean_css),
  copy_vendor,
  generate_qual_html)
exports.jshint = linter