Touch events do not work when <Select /> is mounted in a shadow root

[mbeckem]

Hi,

the current approach to touch event handling does not work well when <Select /> is used with a shadow root.

Reproduction

• Open Stackblitz: https://stackblitz.com/edit/stackblitz-starters-pandyv?file=src%2FApp.tsx
• The Select component works well using clicks (the Menu opens when clicking into the input)
• Open your browser's mobile device emulation (or use a touch device) and touch into the input field
• The menu does not open

Notes

• The menu actually opens internally, but it is hidden immediately because the onTouchEnd event handler categorizes the touch event as outside the select control (this results in a blurInput() call)
• When inside a shadow root, the event handler registered on the document will not observe the original .target, but the entire shadow dom. This is obviously not contained in the original node, which causes the behavior in this case.
• A more stable alternative to .contains(...) is to use event.composedPath() instead. See also this blog post.

I've had trouble creating a unit test for this bug (I could not get touch events inside shadow DOM to work with jest). I hope that the sample above will be sufficient.
I think a fix would look as simple as replacing node.contains(event.target) with event.composedPath().includes(node). I'll gladly create a PR for this.

Kind regards

[mbeckem]

Related: PR #5737 attempts to fix this issue, but I think the approach taken is not optimal

[vpenchev-noteris]

+1