(fix) - transitions

[JoviDeCroock]

Fixes: #1798

This PR should serve as a deciding point whether or not we want to support these cases to improve React compat.

[coveralls]

Coverage increased (+0.9%) to 99.69% when pulling df21479 on fix/transitions into 8ab4239 on master.

[fjorgemota]

Hey.

Thanks for the PR! :)

Even throught I mentioned specifically onTransitionEnd on the issue, I think there's other events that probably would be worked around too on preact/compat. #1589 with it's onAnimationEnd is one of these examples.

So...maybe we should use a generic code like the one found on #1590 to detect which events to patch for, and maybe verifying if the attribute doesn't exist on DOM element first?

I don't know..these are just ideas. But anyway thanks for the PR. I hope I can help on the discussion. =)

[JoviDeCroock]

@fjorgemota this PR is intended as a starting point for discussing if we want to support these events. The solution of #1589 can't be used since this breaks testing envs. If we would agree on this I would suggest looking for the postfix start/end and using that to determine a toLowerCase()

[fjorgemota]

@JoviDeCroock oh. Ok then. Fair enough. I'm waiting for the reviews and further discussion, then. Thanks! :)

[developit]

A thought: for DOM nodes (typeof vnode.type == 'string'), loop over props and lowercase any keys matching /^on(ani|tra)/.

[JoviDeCroock]

@developit yes, so we want to support these?

[marvinhagemeister]

Love the golfing! Putting it into applyEventNormalization is the right way forward. Thank you so much for another awesome PR 🎉