Support events on buttons/links/forms in ShadowDOMs

[jethron]

When DOM events on elements within Custom Components/ShadowRoots trigger against the document, the target is set to the Custom Element/shadow host rather than the actual element that caused the event.

This change adds support to the from/button/link tracking plugins to detect when this occurs, and use the first element from the Event's composedPath instead of the target. This enables them to see the actual even target and fire correctly in this scenario.

For the Form tracker, only focus events are considered composed, so change and submit events don't actually get reported outside the shadow DOM. As a workaround, when the focus events occur, if enabled the change/submit event listeners are bound directly to the form (or field if it has no associated form) rather than just the document.

[bundlemon]

BundleMon

Files added (6)

Status	Path	Size	Limits
✅	trackers/javascript-tracker/dist/sp.js	+24.32KB	30KB / +10%
✅	libraries/browser-tracker-core/dist/index.mod ule.js	+23.41KB	25KB / +10%
✅	libraries/tracker-core/dist/index.module.js	+19.12KB	20KB / +10%
✅	trackers/browser-tracker/dist/index.umd.min.j s	+17.24KB	20KB / +10%
✅	trackers/javascript-tracker/dist/sp.lite.js	+17.18KB	20KB / +10%
✅	trackers/browser-tracker/dist/index.module.js	+3.49KB	5KB / +10%

Total files change +104.75KB 0%

Final result: ✅

View report in BundleMon website ➡️

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Current branch size history

[matus-tomlein]

LGTM! 👍