I went through a phase of this when I started writing automated tests. It occurred when I started using a mocking library for the first time. The library was

I went through a phase of this when I started writing automated tests. It occurred when I started using a mocking library for the first time. The library was so advanced I could basically test my implementation instead of my api. EG: "first you call foo.bar(), then you call foo.baz()" As a result, my test and my system under test looked very similar. I'm not sure if you're in the same situation I was in, but let me tell you: My situation was an anti-pattern. All I was testing was that my code does what it does. I wasn't testing that my code was working. Make sure you're not making the same mistake. If you are, a symptom would be that lots of tests fail when you're only refactoring.