They are for sure! Obviously, all depends on the complexity of the problem and the willingness of programmers to install tests :/ In my company, we are ridicul

They are for sure! Obviously, all depends on the complexity of the problem and the willingness of programmers to install tests :/ In my company, we are ridiculously pedantic about unit testing, but even with proper level of attention to detail we sometimes fail with getting 100% code coverage. The biggest pain are log(x)/ln(x) issues in numerical optimization.