I've been learning test-driven development over the last couple of days. The process has gotten me to become much more careful with my code...but perhaps too careful.

I was always the type of programmer that rarely validated arguments passed to subroutines. If an argument was passed that was not the expected format, the program would behave unexpectedly or crash and then I'd deal with it. With test-driven development, I'm finding myself writing tests to ensure a subroutine returns the appropriate error message if a passed argument is not what the subroutine expects.

This is certainly a lot more work. Though I'm sure it makes my code is more robust, I'm wondering at what cost. I'm not writing code for banking institutions or space programs, after all.

So I'm wondering how other Monks approach argument validation. Is this something you do diligently and is considered to be best practice? Do you think it's worth the time to write tests to ensure subroutines handle bad arguments? Are you using modules like Param::Validate to check subroutine arguments? Any other thoughts on argument validation you'd like to share?

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In reply to Is validation of all subroutine arguments overkill? by nysus

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