Don't worry about what other people do. Write as many tests as you need and don't worry too much if you have some extra. Don't think of tests in terms of lines of code. Test things that do something. Everything that does something gets a test. Test for expected input, unexpected input, and every situation you can think of, even if you think it's trivial. Use a coverage tool to ensure you test everything.

If you go back and refactor the tests to bring down the line count, great. If not, oh well. Worrying about the line count as the main goal is only going to get in the way of your testing mindset.

If you are still curious, simply download some CPAN modules and look for yourself. :)