in reply to Working with old code

Write tests for every single part of the business in:out you can possibly figure out. Perl testing, even system testing, is extremely easy and flexible once you get a feel for it. Once you have a deep test suite, you can refactor with confidence and speed because you will know immediately if you broke something or changed behavior.

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Re^2: Working with old code
by toolic (Bishop) on Jun 26, 2020 at 20:22 UTC
    ++ ... and run coverage (Devel::Cover) to prove the tests hit what you expect them to hit.