who needs jsx?

h.js

function h(tag, props = {}, children = null) {
  if (arguments.length === 2 && props && (typeof props !== 'object' || Array.isArray(props))) {
    children = props
    props = {}
  }

  const inner = children ? [].concat(children).join('') : ''

  if (!tag) {
    return inner
  }

  const htmlProps = Object.entries(props).map(([k, v]) => `${k}="${v}"`)
  const start = `<${[tag].concat(htmlProps).join(' ')}>`
  const end = `</${tag}>`
  return [start, inner, end].join('')
}