Yes, exactly, this is mutation testing. It's been on the Devel::Cover TODO list for years (item 7 at https://st.aticpan.org/source/PJCJ/Devel-Cover-1.23/docs/TODO). It doesn't have to be done as a part of Devel::Cover, but the advantage to that approach is that Devel::Cover knows which tests exercise the ops being changed and so can only run those tests. Otherwise the whole thing can get even more expensive than it already is.

This disadvantage to that approach, obviously, is that no one has done it.

In reply to Re^2: Testing my tests by pjcj
in thread Testing my tests (mutation testing) by szabgab

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