index.js

module.exports = function (app, opts) {
  return function (props) {
    opts = opts || {}
    var storage = opts.storage || 'hyperapp-persist'
    var include = opts.include || []
    var _init = props.init
    
    props.init = function (state, actions) {
      if (_init) _init.apply(null, arguments)

      var data = localStorage.getItem(storage)
      if (data) actions.__restore(JSON.parse(data))
      
      window.addEventListener('unload', function () {
	actions.__save()
      })
    }

    props.actions.__restore = function (_s, _a, previous) {
      return previous
    }
    
    props.actions.__save = function (state) {
      localStorage.setItem(storage, JSON.stringify(state, include))
    }
    
    return app(props)
  }
}