Create common,vendor and several entry point bundles using systemjs-builder

systemjs-builder-code-splitting.js

let Builder = require('systemjs-builder');
let fs = require('fs');
let mapValues = require('lodash/mapValues');

let config = {
  baseURL: '.',
  map: {
    'vendor': 'lib/vendor'
  }
};

let b = new Builder('.');
b.config(config);

(async function(){
  try { 
    let vendor = 'output/vendor.js';
    let common = 'output/common.js';
    let entry1 = 'output/entry1.js';
    let entry2 = 'output/entry2.js';

    let bundles = {
      [vendor]: await b.bundle(`(entry1.js + entry2.js) & (lib/vendor/*.js)`, vendor),
      [common]: await b.bundle(`(entry1.js & entry2.js) - ${vendor}`, common),
      [entry1]: await b.bundle(`entry1.js - ${common} - ${vendor}`, entry1),
      [entry2]: await b.bundle(`entry2.js - ${common} - ${vendor}`, entry2)
    };

    Object.assign(config, {
      bundles: mapValues(bundles, v => v.modules)
    });

    console.log(JSON.stringify(config.bundles, null, 2));

    fs.writeFileSync(
      'output/system-config.js', 
      `System.config(${JSON.stringify(config, null, 2)})`);
    
    console.log('Build complete');
  }catch(e){
    console.log('Build error', e);
  }
})();