Test page crashes.

[fdrobidoux]

Seems like your test page crashes for me.

Gamepad connected at index 0: Unknown Gamepad (Vendor: 0000 Product: 0000). 0 buttons, 16 axes.
single-gamepad.js:14 no mapping found, using default for Unknown Gamepad (Vendor: 0000 Product: 0000) on Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36
SingleGamepad.detectMapping @ single-gamepad.js:14
single-gamepad.js:52 Uncaught TypeError: Cannot read property 'pressed' of undefined
    at SingleGamepad.button (single-gamepad.js:52)
    at gamepad-diagram.jsx:8
    at Array.map (<anonymous>)
    at GamepadDiagram (gamepad-diagram.jsx:8)
    at ReactCompositeComponent.js:306
    at measureLifeCyclePerf (ReactCompositeComponent.js:75)
    at ReactCompositeComponentWrapper._constructComponentWithoutOwner (ReactCompositeComponent.js:305)
    at ReactCompositeComponentWrapper._constructComponent (ReactCompositeComponent.js:280)
    at ReactCompositeComponentWrapper.mountComponent (ReactCompositeComponent.js:188)
    at Object.mountComponent (ReactReconciler.js:46)
index.js:4 Gamepad connected at index 1: Xbox 360 Controller (XInput STANDARD GAMEPAD). 17 buttons, 4 axes.
single-gamepad.js:10 found mapping Xbox 360 Chrome Windows/OSX for Xbox 360 Controller (XInput STANDARD GAMEPAD) on Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36
single-gamepad.js:52 Uncaught TypeError: Cannot read property 'pressed' of undefined
    at SingleGamepad.button (single-gamepad.js:52)
    at gamepad-diagram.jsx:8
    at Array.map (<anonymous>)
    at GamepadDiagram (gamepad-diagram.jsx:8)
    at ReactCompositeComponent.js:306
    at measureLifeCyclePerf (ReactCompositeComponent.js:75)
    at ReactCompositeComponentWrapper._constructComponentWithoutOwner (ReactCompositeComponent.js:305)
    at ReactCompositeComponentWrapper._constructComponent (ReactCompositeComponent.js:280)
    at ReactCompositeComponentWrapper.mountComponent (ReactCompositeComponent.js:188)
    at Object.mountComponent (ReactReconciler.js:46)

Using Chrome Version 71.0.3578.98 (Official Build) (64-bit)
On Windows 10 Pro
With an official Xbox One wireless controller.