Update `triggerKeyEvent` to handle `code` and `key`.

From https://github.com/emberjs/ember-test-helpers/pull/258#discussion_r155963086:

When I initially copied keyEvent, I continued to use keyCode as the main way to set the key, but it seems to be deprecated and the new alternatives are KeyboardEvent.code and KeyboardEvent.key, specially the last one.

Perhaps we might want to start using it, or maybe assume that integers mean keyCode and strings mean key.

[gossi]

Same here, code isn’t set. Here is the workaround:

await triggerKeyEvent('[data-test-code-input-1]', 'keydown', 'Digit4', {code: 'Digit4'});

Also will provide squiggly red lines if you are using TS 😦. May I suggest this API:

triggerKeyEvent(target: Target, eventType: KeyboardEventType, key: number | string, modifiers: KeyModifiers = DEFAULT_MODIFIERS);
triggerKeyEvent(target: Target, eventType: KeyboardEventType, key: number | string | Props);

where Props is the KeyboardEventInit. This way it is BC but will provide the flexibility we have to deal with when handling key events.

[istateside]

Sorry to resurrect an old issue, but was the code property intentionally left out of the fix here? I’ve got a failing test because we’re using a keyboard shortcut that relies on the code property. I had skipped the test and added a comment linking to this issue, thinking that it would eventually be fixed. We can refactor to use something else, but is there a reason why code was not implemented?

From my understanding, key and code are both supported for different reasons- key gives you the string ‘value’ of a keypress, whereas code is useful for telling which physical button was pressed, regardless of keyboard layout or language.