A commercial Vaadin subscription is required to use TestBench in your project.
TestBench UI unit testing is browser-less, so you look up components straight from
You call methods directly on your server-side view classes and on the server-side Java Vaadin components.
Because UI unit testing is also container-less, you do not need to launch the servlet container.
UIUnitTest class handles creating the Vaadin session, the UI and other necessary Vaadin classes right in the JVM that runs your JUnit tests.
In addition to UI unit testing, TestBench also enables you to write end-to-end tests for your Vaadin applications. Each approach has their own advantages.