Should I unit test my Cucumber helper functions/classes?

Question

I'm very new at writing Cucumber tests. I'm writing Ruby helper functions to assist Cucumber step definitions. Should there be a separate set of tests to test my helper functions i.e. unit tests?

The step definitions are using the helper functions but there's nothing really testing that the helper functions are working as they should.

Does anyone unit test their Cucumber support helpers?

Answer 1

I would say no, for the same reason you don't write unit tests for unit tests. Tests are written to verify functionality. They should be considered part of the functionality itself: when you change the functionality, you change the tests. There's no point in writing a test of the test when you can just fix the test itself.

To answer your implied question of how you make sure the test is working like it should: The best way to ensure that the test both fails appropriately and passes correctly is to write it first. Write a failing test and make it pass. See the following for reference:

• https://semaphoreci.com/community/tutorials/introduction-to-writing-acceptance-tests-with-cucumber
• https://www.ctl.io/developers/blog/post/acceptance-tdd-cucumber

This is a recommended practice in Acceptance Test Driven Development (ATDD) and Behavior-Driven Development (BDD).