fix(EventStack): fix compatibility with IE11

[layershifter]

Fixes #3043.

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What was done?

Move to a separate repo

EventStack was moved to separate package and was published as @semantic-ui-react/event-stack.

Motivation: this package requires a specific test config for browsers. However, I'm not happy with this decision, I prefer monorepos 😺 Possible, Stardust will adopt it.

Browser compability

EventStack is now fully compatible with IE11. To avoid regresions I added browser tests:

• Chrome & Firefox: https://circleci.com/gh/layershifter/event-stack
• IE11: https://ci.appveyor.com/project/layershifter/event-stack

Performance 🚀

I and my сolleagues carefully profiled this part of the lib, performance was drasticaly improved. The most slow was EventSet:

• constructor() - almost 10x
• addHandlers() - almost 10x
• dispatchEvent() - 10x for default pool, 1.5x for named pool
• removeHandlers() - almost 5x

Feel free to edit benchmarks and propose more performant solution.

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There I also couple serious bugs with EventStack event handling, I will concentrate on them after merge. I'm also planning to move #2990 to this package.

[codecov-io]

Codecov Report

Merging #3124 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3124   +/-   ##
=======================================
  Coverage   99.92%   99.92%           
=======================================
  Files         163      163           
  Lines        2742     2742           
=======================================
  Hits         2740     2740           
  Misses          2        2

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[levithomason]

Possible, Stardust will adopt it.

Yes please!

[levithomason]

We have a fork of this in Stardust as well. Yes, I would love to have a single utility here. It is also duplicated in Fabric (Microsoft). One of the goals of Stardust is to normalize these kinds of utilities between frameworks. Let's merge this for now, then we can port it to Stardust and publish it as a monorepo.

There might still be a bug here, not sure. Here's what I think I've found. I noticed the bug in #3062 goes away if we fix the sub method. Currently, the entire pool is removed then re-added on sub. However, the pool shares handlers with other components under the same pool name. When a second Dropdown opens it calls sub for close on document click, which removes the entire pool (including the first Dropdown's close on document click), then adds only the second Dropdown's close on document click.

When I use document.addEventListener instead, all works as expected. When I remove the line in EventStack that removes the entire pool on sub, all works fine as well. So, I think we need to skip sub if that handler already exists and not remove/add the entire pool.

[levithomason]

Released in [email protected].