keyboardevent-code is not supported in IE due to which key navigation does not work

[ghost]

Referring: https://caniuse.com/#feat=keyboardevent-code, IE lack keyboardevent-code support yet.

Solution -
tried using:
let code1 = '';
if (!event.code) {
if (event.keyCode) {
if (event.keyCode === 40) {
code1 = 'ArrowDown';
} else if (event.keyCode === 38) {
code1 = 'ArrowUp';
}
}
} else {
code1 = event.code;
}

So need fixes or if poly-fill can be used. Please let me know, if I can raise a PR for the same.

[platzhersh]

I found out this polyfill here helps: https://github.com/inexorabletash/polyfill/blob/master/keyboard.md