Large test suites often contain many tests that are absolutely redundant. They overlap with other tests so much that they only find bugs that these other tests already find. Such redundant tests are not only useless, but harmful: They slow down test execution without adding value in terms of bug-finding capability. And even worse, they eat up effort to maintain that would be better spent elsewhere. So let’s remove them!

 

But how can we detect redundant tests in our large test suites? And how can we be sure that they really provide no value?

 

In my talk, I will present several approaches to identify redundant tests. I will share their research background, our empirical studies and our experiences with how well they work under which conditions.