React with ES6

App.js

/*
  Before: Without ES6
*/
var App = React.createClass({
  getInitialState : function() {
    return {
      fishes : {},
      order : {}
  },
  //...
})

/*
  After: With ES6
*/

class App extends React.component{
  constructor() {
    super()
    this.state = {
      fishes : {},
      order : {}
    }
  }
}