React: Keyboard Event Handlers All ‘Null’

BinaryMuse provided the answer on IRC. Turns out it’s just a quirk; you can’t read the properties directly from SyntheticKeyboardEvent — you need to specify the properties from the handler:

handleKeyUp: function(e) {
 console.log(e.type, e.which, e.timeStamp);
},

http://jsfiddle.net/BinaryMuse/B98Ar/