text: const loader = require('./loader');
  const UglifyJS = require("uglify-js");
  const fs = require('fs');
  const apps = require('./applications');
  
  const cache = [];
  const bundleName = 'bundle';
  const devName = `${bundleName}.js`;
  const prodName = `${bundleName}.min.js`;
  let bundle = fs.openSync(devName, 'w');
  
  function appendFile(file) {
      console.log(`append file : ${file}`);
      let content = fs.readFileSync(file);
      fs.appendFileSync(devName, content);
  }
  
  apps.forEach(filename => {
      let requires = loader(filename);
      requires.order.forEach(file => {
          if(!cache.includes(file)) {
              cache.push(file);
          }
      });
  });
  
  cache.forEach(file => {
      appendFile(file);
  });
  console.log(`Cache size is ${cache.length} file(s)`);
  fs.closeSync(bundle);
  
  const code = fs.readFileSync(devName, "utf8");
  
  bundle = fs.openSync(prodName, 'w');
  fs.appendFileSync(prodName, UglifyJS.minify(code).code);
  fs.closeSync(bundle);
  