Mutation testing is a silver bullet for assessing test quality. Mutation testing will help you:
Write better tests
Produce more robust code that better handles edge cases
Reveal what parts of your legacy application are most likely to break before you dive in to make new changes
Learn about features in Ruby and your dependencies that you didn’t previously know about
This talk assumes a basic knowledge of Ruby and testing. The examples in this talk will almost certainly teach you something new about Ruby!