umbraco-unit-testing

To unit test Umbraco backoffice extensions built with Lit, use @open-wc/testing with Web Test Runner to validate context tokens, observable subscriptions, and shadow DOM rendering in isolation. You can choose full Umbraco imports or mock-based approaches for faster feedback.

Umbraco Lit module imports fail in Web Test Runner when import maps do not correctly target the dist-cms package/lib structure. Configuring accurate import map paths ensures reliable module resolution for backoffice Lit, context, and observable APIs during test execution.

Yes, you can use mock-based isolation instead of full Umbraco imports for testing simpler logic-only scenarios. This approach provides faster feedback by avoiding full context consumption and UUI rendering setups, while still validating core observable state and controller utilities.

The best way to test shadow DOM rendering and observable state in Umbraco is applying deterministic Web Test Runner workflows with @open-wc/testing. This verifies that observable context updates correctly drive UI re-rendering for Lit elements without slow end-to-end setups.

Yes, you need @web/test-runner-playwright to run isolated component tests for Umbraco backoffice UI. It satisfies the required tooling setup alongside @open-wc/testing, enabling fast and deterministic validation of Lit elements and context logic.