open-wc testing issue

Webcomponent project via open-wc.

Refer to:

UPDATE: Working version.

Testing with Web Test Runner

To run the suite of Web Test Runner tests, run

npm run test

To run the tests in watch mode (for <abbr title="test driven development">TDD</abbr>, for example), run

npm run test:watch

Local Demo with web-dev-server

npm start

To run a local development server that serves the basic demo located in demo/index.html