View the demo page, or clone and run yourself.
Use this to test Input Events Level 1/2 support and quirks in browsers. For reference, see the published W3C specs, or the W3C github repo to see discussions and undocumented specs.
To add test cases, simply modify index.html. The JavaScript files are transpiled/bundled using rollup/babel, to work with older browsers that have Input Events implemented:
npm install
npm run bundle