mountWidget centralizes both classic and shadow mounting behind a single
entry point. The shadow path attaches an open shadow root, injects CSS via
constructable stylesheets (with a deduped <style>-tag fallback for jsdom
and Safari < 16.4), and renders Preact into a stable inner wrapper so the
sibling style node is not clobbered by render() diffs.
applyStyles is exported separately so the fallback branch can be exercised
directly in unit tests without a full mount round trip — the constructable
path runs only in real browsers.
Idempotency on the host element and shadow root means repeated boots
(HMR, accidental double-load) do not duplicate DOM nodes.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds the boolean field consumed by the upcoming Shadow DOM mount path.
Strict equality with the string "true" — anything else (absent, "false",
"1", "yes", empty) yields false, so accidental opt-in is impossible.
Tests cover the full parseConfig surface (required fields, server-url
derivation, position default) plus the new shadow attribute parsing.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Add vitest 4.1, jsdom 25, and @testing-library/preact as devDeps so the
widget gets a real test surface for the upcoming Shadow DOM mount work.
- vitest.config.ts mirrors the build aliases (preact/compat) and uses
jsdom for DOM-touching tests.
- tests/setup.ts is the place to add polyfills as the surface grows.
- tests/unit/smoke.test.ts confirms vitest runs, jsdom is wired, and
Shadow DOM API is available.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
