Shoelace and Cypress
TL;DR:
            For the most part, you can use Shoelace components the same way you’d use their HTML equivalents, since they
            emit many of the same events (click, focus, etc). But like all web components,
            Shoelace components encapsulate their internal parts within the
            shadow dom. This means that the internals of Shoelace components aren’t available directly on the DOM (via
            document.querySelector, etc.), but have to be queried via the
            Element.shadowRoot property.
          
            Cypress provides a convenience method for accessing the shadow dom via the
            .shadow() method..
          
cy.get('sl-button[href]').shadow().find('a'); // Will find the anchor tag within a link button cy.get('[data-test-id="some_sl_button"]').click(); // Should work fine on a button where id is set at the top level
More tips coming soon! (And remember, you too are free to contribute to this guide!)