gulpfile.js

'use strict';
const gulp = require('gulp'),
  source = require('vinyl-source-stream'),
  concat = require('gulp-concat'),
  header = require('gulp-header'),
  uglify = require('gulp-uglify-es').default,
  streamify = require('gulp-streamify'),
  browserify = require('browserify'),
  packageFile = require('./package.json');

const config = {
  src: './src/index.js',
  outDir: './dist/',
  outName: 'chartjs-plugin-gantt.js',
  outNameMin: 'chartjs-plugin-gantt.min.js',
};

const git = packageFile.homepage.replace(/\#.*/, '');

const hdr = '/*!\n\
 * chartjs-plugin-gantt\n\
 * ' + packageFile.homepage + '\n\
 * Version: ' + packageFile.version +'\n\
 *\n\
 * Copyright 2019 Anton Shchyrov\n\
 * Released under the Apache 2.0 license\n\
 * ' + git + '#LICENSE\n\
 */\n\n';

gulp.task('build-prod', buildProd);
gulp.task('build-dev', buildDev);

function prepare(debug) {
  const res = browserify(
    {
      entries: config.src,
      debug: debug,
    })
    .plugin('esmify');
  if (!debug)
    res.external('chart.js');
  return res
    .bundle()
    .pipe(source(config.outName))
    .pipe(header(hdr))
    .pipe(gulp.dest(config.outDir));
}

function buildProd() {
  return prepare(false)
    .pipe(streamify(uglify()))
    .pipe(streamify(concat(config.outNameMin)))
    .pipe(gulp.dest(config.outDir));
}

function buildDev() {
  return prepare(true);
}