Keep the faith, Brother!

Having been a Smalltalk user for at least 5 years now, one thing that helps in typical Smalltalk environments is their checking of method names when you define new methods. Every time you edit a method, it's recompiled; the compiler does a simple check to see if any of the method names you're using haven't been defined yet. If so, you get a warning. This has helped me detect a lot of typos in my code.

I'm thinking that a similar strategy could be used with Perl, by scanning programs like this:

• For each 'use'd or 'require'd package, make a defined symbol list (easiest way to do this is probably just to use B::Xref).
• Scan your program for method calls (or, more simply, for words, removing all the Perl pre-defined words).
• Make a list of all the method calls (or words) in your program that don't match any of the subroutines defined in your included packages

This is a simple strategy, and it should be easy to implement. Tell me if it works!

I still prefer full testing, though. Have you read anything about Extreme Programming techniques? One of the XP tenets is to write tests FIRST.