Fix onMouseEnter is fired on disabled buttons

[AlfredoGJ]

This pull request fixes issue #17229. I modified shouldPreventMouseEvent function to include onMouseEnter and added a new test to ReactBrowserEventEmmiter-test.

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 64336e9:

Sandbox	Source
twilight-sound-902nk	Configuration

[sizebot]

	Warnings
⚠️	Base commit is broken: 1b9328c

Size changes (experimental)

Generated by 🚫 dangerJS against 64336e9

[sizebot]

	Warnings
⚠️	Base commit is broken: 1b9328c

Size changes (stable)

Generated by 🚫 dangerJS against 64336e9

[benbot]

should onMouseExit be on that switch statement as well?

[AlfredoGJ]

@benbot Unlike onMouseEnter, onMouseExit performs well and has not the same bug. onMouseExit event is not even generated for a disabled button. I'm thinking that maybe none of these event names should be in that switch statement and the bug is in the event registration phase.

I 'll be doing deeper research these days. Meanwhile, this could a useful workaround for someone.

[StefanNieuwenhuis]

👍

[trueadm]

This seems okay to me. Ideally we should remove all the custom disabled logic and come up with a better solution in the future for the event system, but for now this should fix this issues at hand.

[mohsinulhaq]

This fixes #4251 as well, right?

[LordSeb]

What if you want to display tooltip / help text why user cannot perform action connected with disabled button when user hovers the button? (my real world case). The fix should be to make onMouseExit enabled and have both enabled and not disable the onMouseEnter. If you know nice way (not hack like fake-disable button) how to solve my example case without onMouseEnter onMouseEnter I am free to discuss. But otherwise it should be both enabled in my opinion.

disabled button should just not perform event (on click) but the users still should know why they cannot perform the events (on hover)

[gaearon]

Can you please file a new issue to discuss?