Q:

How to integrate Vaadin with Cucumber

Is there a way to integrate Vaadin7 with Cucumber? Can Vaadin Testbench help me with this task? Is Vaadin Testbench necessary for this task?

A:

Cucumber just executes the gherkin scenarios. The integration between vaadin and cucumber is in fact an integration between vaadin and selenium on the one side and selenium and cucumber on the other side.
You will have to write glue-code and steps that work with selenium webdrivers which encapsulates the vaadin pages.
If you are not experienced with these domains it is probably the best to buy a license for the testbench. You don't need it if you are able and willing to provide the needed drivers and settings yourself. 
Take a look at this project to get some inspirations: https://github.com/holisticon/demo-cucumber-vaadin (demo uses guice and vaadin6 so it might not fit but will show some basic set up)

