something.js

const input = require('./my-thing.gui')

const parse = (obj, html = "") => {


  Object.keys(obj).forEach(key => {
    const element = obj[key]

    switch (element.type) {
      case 'button':
        html += `<button>${parse(element.children, html)}</button>`
        break;
      case 'input':
        html += `<input />`
        break;
    }

    return html
  })
}

const output = parse(input)

Fs.writeFileSync('./my-thing.html', output)