Remove `keydown` linting in rule: no-down-event-binding

no-down-event-binding rule includes keydown event:

https://github.com/ember-template-lint/ember-template-lint/blob/master/docs/rule/no-down-event-binding.md

I understand how binding to mousedown could cause a11y issues because it prevents a user from moving away from the target(preventing the action). However, I do not see the benefit for avoiding keydown. Once the key is pressed a user can’t really undo it. But maybe I’m not seeing something.

It is known that keydown provides more uniform behavior across different browsers. https://www.mutuallyhuman.com/blog/keydown-is-the-only-keyboard-event-we-need/

Hello @MelSumner , I see that you contributed to this rule. What is the original reasoning behind including keydown along with mousedown?

Talking with our a11y team, they agree that it is fine to use keydown without compromising a11y.

Please let me know, if the community agrees, I can work on submitting a PR.
Thank you, Mario

[drewlee]

@MelSumner The tab example behavior may not be desirable for all cases. For example, if we have a vertical tab component, we would want to stop the browser from scrolling the page each time the Up and Down arrow keys are pressed to activate a tab. There are similar concerns with combobox-like components, where list scrolling behavior may require programmatic control. Doing this requires adding a keydown event listener in order to apply preventDefault. A better approach to limiting sequential key triggers would be to implement a debounce. Overall, this seems to be too much of a narrow use case to broadly ban all usage of keydown.

[MelSumner]

Update: an example where you would want to use keyup instead of keydown: On a tabs component, you would want to configure the arrow keys that cycle between the tabs to use keyup instead of keydown- keyup responds once, whereas keydown would respond multiple times. This would be detrimental for folks with motor control issues.

I wonder if we should keep this rule as is and instead encourage folks to disable it if they really feel like they need to use it.