Gulp javascript task — browserify version

gulpfile.js

let PRODUCTION_MODE = process.argv.indexOf('--minify') !== -1;

const gulp = require('gulp');
const _ = require('gulp-load-plugins')();
const fs = require('fs');

gulp.task('javascript', () => {
  const browserify = require('browserify');

  const tasks = ['./source/js/index.js', 'source/js/sw.js']
    .map(entry => {
      if (!fs.existsSync(entry)) {
        return;
      }

      return browserify({ entries: entry, debug: !PRODUCTION_MODE })
        .transform(require('babelify'), {
          presets: ['@babel/preset-env'],
          sourceMaps: !PRODUCTION_MODE,
        })

        .bundle()
        // Optional
        // .on('error', _.errorNotifier.notify)
        // .pipe(_.errorNotifier())

        .pipe(require('vinyl-source-stream')(entry))
        .pipe(require('vinyl-buffer')())

        .pipe(
          _.rename({
            dirname: '',
          })
        )

        .pipe(_.if(PRODUCTION_MODE, _.streamify(_.terser())))

        .pipe(gulp.dest('./public/assets/js'))
    })
    .filter(task => task);
});

package.json

{
  "scripts": {
    "build": "gulp javascript --minify"
  },
  "dependencies": {
    "@babel/core": "7.2.2",
    "@babel/preset-env": "7.2.0",
    "babelify": "10.0.0",
    "browserify": "16.2.3",
    "gulp": "^3.9.1",
    "gulp-if": "^2.0.2",
    "gulp-load-plugins": "^1.5.0",
    "gulp-rename": "1.4.0",
    "gulp-streamify": "1.0.2",
    "gulp-terser": "^1.1.6",
    "vinyl-buffer": "1.0.1",
    "vinyl-source-stream": "2.0.0"
  }
}