gulpfile.js

const gulp = require('gulp')
const rollup = require('gulp-rollup')
const gulpif = require('gulp-if')
const uglify = require('gulp-uglify')
const rename = require('gulp-rename')
const css2js = require('gulp-css2js')
const concat = require('gulp-concat')
const autoprefixer = require('gulp-autoprefixer')
const cleanCss = require('gulp-clean-css')
const babel = require('rollup-plugin-babel')
const json = require('rollup-plugin-json')
const merge = require('merge2')
const sass = require('sass')
const browserSync = require('browser-sync').create()
const packageJson = require('./package.json')
const execute = require('@sweetalert2/execute')
const log = require('fancy-log')
const fs = require('fs')
const version = process.env.VERSION || packageJson.version

const banner = `/*!
* ${packageJson.name} v${version}
* Released under the ${packageJson.license} License.
*/`

const srcScriptFiles = ['src/**/*.js']
const srcStyleFiles = ['src/**/*.scss']

const continueOnError = process.argv.includes('--continue-on-error')
const skipMinification = process.argv.includes('--skip-minification')
const skipStandalone = process.argv.includes('--skip-standalone')

// ---

gulp.task('clean', () => {
  if (!fs.existsSync('dist')) {
    fs.mkdirSync('dist')
  }

  return fs.promises.readdir('dist')
    .then(fileList => {
      if (fileList.length > 0) {
        const unlinkPromises = []
        fileList.forEach(fileName => {
          unlinkPromises.push(fs.promises.unlink(`dist/${fileName}`))
        })
        return Promise.all(unlinkPromises)
      }
    }).catch(error => {
      if (error.code !== 'ENOENT') {
        return Promise.reject(error)
      }
    })
})

gulp.task('build:scripts', () => {
  return gulp.src(['package.json', ...srcScriptFiles])
    .pipe(rollup({
      plugins: [
        json(),
        babel({
          exclude: 'node_modules/**'
        })
      ],
      input: 'src/sweetalert2.js',
      output: {
        format: 'umd',
        name: 'Sweetalert2',
        banner: banner,
        footer: `\
if (typeof this !== 'undefined' && this.Sweetalert2){\
  this.swal = this.sweetAlert = this.Swal = this.SweetAlert = this.Sweetalert2\
}`
      }
    }))
    .on('error', (error) => {
      if (continueOnError) {
        log(error)
      } else {
        throw error
      }
    })
    .pipe(gulp.dest('dist'))
    .pipe(gulpif(!skipMinification, uglify()))
    .pipe(gulpif(!skipMinification, rename('sweetalert2.min.js')))
    .pipe(gulpif(!skipMinification, gulp.dest('dist')))
})

gulp.task('build:styles', () => {
  const result = sass.renderSync({ file: 'src/sweetalert2.scss' })
  fs.writeFileSync('dist/sweetalert2.css', result.css)

  return gulp.src('dist/sweetalert2.css')
    .pipe(autoprefixer())
    .pipe(gulp.dest('dist'))
    .pipe(gulpif(!skipMinification, cleanCss()))
    .pipe(gulpif(!skipMinification, rename('sweetalert2.min.css')))
    .pipe(gulpif(!skipMinification, gulp.dest('dist')))
})

/**
 * Warning: This task depends on dist/sweetalert2.js & dist/sweetalert2.css
 */
gulp.task('build:standalone', () => {
  const prettyJs = gulp.src('dist/sweetalert2.js')
  const prettyCssAsJs = gulp.src('dist/sweetalert2.min.css')
    .pipe(css2js())
  const prettyStandalone = merge(prettyJs, prettyCssAsJs)
    .pipe(concat('sweetalert2.all.js'))
    .pipe(gulp.dest('dist'))
  if (skipMinification) {
    return prettyStandalone
  } else {
    const uglyJs = gulp.src('dist/sweetalert2.min.js')
    const uglyCssAsJs = gulp.src('dist/sweetalert2.min.css')
      .pipe(css2js())
    const uglyStandalone = merge(uglyJs, uglyCssAsJs)
      .pipe(concat('sweetalert2.all.min.js'))
      .pipe(gulp.dest('dist'))
    return merge([prettyStandalone, uglyStandalone])
  }
})

gulp.task('build', gulp.series(
  'clean',
  gulp.parallel('build:scripts', 'build:styles'),
  ...(skipStandalone ? [] : ['build:standalone'])
))

gulp.task('default', gulp.parallel('build'))

// ---

gulp.task('develop', gulp.series(
  'build',
  async function watch () {
    // Does not rebuild standalone files, for speed in active development
    gulp.watch(srcScriptFiles, gulp.parallel('build:scripts'))
    gulp.watch(srcStyleFiles, gulp.parallel('build:styles'))
  },
  async function sandbox () {
    browserSync.init({
      port: 8080,
      uiPort: 8081,
      notify: false,
      reloadOnRestart: true,
      https: false,
      server: ['./'],
      startPath: 'test/sandbox.html'
    })
    gulp.watch([
      'test/sandbox.html',
      'dist/sweetalert2.js',
      'dist/sweetalert2.css'
    ]).on('change', browserSync.reload)
  },
  async function tests () {
    await execute(`karma start karma.conf.js --no-launch`)
  }
))