This is called mutation testing. Here is an article I read recently that I thought was a good introduction to the idea: http://dev.theladders.com/2013/02/muta

This is called mutation testing. Here is an article I read recently that I thought was a good introduction to the idea: http://dev.theladders.com/2013/02/mutation-testing-with-pit-a-step-beyond-normal-code-coverage/ http://dev.theladders.com/2013/02/mutation-testing-with-pit-...