skittish-gamepad.js

// paste this into your console
// Warning: only do this after thoroughly comprehending it because pasting mystery code into your console is bad :p

var doEv=ev=>s=>document.dispatchEvent(new KeyboardEvent(ev,{bubbles:1,keyCode:s.toLowerCase().charCodeAt(0)-32}));
var press=doEv("keydown");
var release=doEv("keyup");

var readGamepad = function() {
    if(navigator.getGamepads()[0].axes[1]>.5) { press("s"); } else { release("s"); }
    if(navigator.getGamepads()[0].axes[1]<-.5) { press("w"); } else { release("w"); }
    if(navigator.getGamepads()[0].axes[0]>.5) { press("d"); } else { release("d"); }
    if(navigator.getGamepads()[0].axes[0]<-.5) { press("a"); } else { release("a"); }
    requestAnimationFrame(readGamepad);
}
requestAnimationFrame(readGamepad);