I'm getting back to Perl programming after a decent chunk of time away from it. Looking back at my old code is making me exceptionally nervous. I haven't noticed any bugs in the last 4 months of running some of it, but I'd like to invest a little time in increasing my peace of mind so I'm looking at different testing approaches.

Looking at some of CPAN's results shows there's no shortage of module options (as I've come to expect from Perl). My question is what recommendations do the monks have for someone new to testing? Which modules should I check out? Thanks.