vnode hook in action

preact.js

/**
 * Module dependencies
 */

const stringify = require('preact-render-to-string')
const preact = require('preact')
const h = preact.h

preact.options.vnode = function (node) {
  if (!node.attributes || !node.attributes.class) return
  if (typeof node.nodeName === 'function') return
  node.attributes.class = node.attributes.class.toString()
}

/**
 * Initialize `App`
 */

const App = (props) => (
  h(Header, props)
)

const Header = (props) => (
  h('div', { class: header() }, `hello ${props.name}!`)
)

function header () {
  return {
    toString: () => 'header'
  }
}

/**
 * Browser
 */

if (typeof document !== 'undefined') {
  preact.render(App({ name: 'matt' }), document.body, document.body.firstChild)
} else {
  console.log(stringify(App({ name: 'matt' })))
}