WebComponent(spec) builds a custom-element base class from a spec:
shadow root or declarative shadow DOM, template, shared stylesheet
(adopted, or a <style> once per root for light DOM), reflected props
with two-way attribute sync, a per-connection AbortSignal, host event
wiring, and typed element refs.
Types derive exact observedAttributes, prop value types, ref element
types from selectors, and reject prop names that collide with the base
class or mixin members.
Tooling: strict tsconfig, type-aware oxlint, oxfmt, and Vitest browser
mode (Chromium) with type tests.