absorb.js

// abs.js
const FILES = require('fs');
module.exports = {
  absorb: (htmlPath) => {
    let html = FILES.readFileSync(htmlPath, 'utf8');
    
    html = html.replace(/(<absorb\s(.+)\/>)/g, function(absorbElement) {
      let filePath = '', fileType = '', jsMod = '';

      if (absorbElement.indexOf('css=') >= 0) {
        fileType = 'css';
        filePath = absorbElement.slice(
          absorbElement.indexOf('css=') + 5,
          absorbElement.indexOf('/>') - 1
        ); // filePath

      } else if (absorbElement.indexOf('js=') > -1) {
        jsMod = (absorbElement.indexOf(' defer ') > -1 ? ' defer' : '');
        jsMod = (absorbElement.indexOf(' async ') > -1 ? ' async' : '');
        fileType = 'js';
        filePath = absorbElement.slice(
          absorbElement.indexOf('js=') + 4,
          absorbElement.indexOf('/>') -1
        ); // filePath
      }; // if/else

      let code = FILES.readFileSync(filePath, 'utf8');

      if (fileType == 'css') return `<style>${code}</style>`;
      if (fileType = 'js') return `<script${jsMod}>${code}</script>`;
      return `<script async>alert('ERR: ${filePath}')</script>`;
    }); 

    return html;
  } // absorb()
}; // module.exports