Functional stubs for DOM objects needed for web component testing, using all built-in objects the environment has rather than replacing them.
This came out of our need to programmatically test our Web Components plugins but all available shims we tried (jsdom, happy-dom, even @lit-labs/ssr-dom-shim) either replaced the built-in objects that NodeJS did have (Event, EventTarget, CustomEvent etc) or were completely non-functional stubs.