kentcowgill.org/blog

&qidYou may have guessed by now, but I've taken up a particularly onerous gauntlet at my job. I'm afraid to touch any modules. But holy cow, do they need touching.

What do we learn from Refactoring: Improving the Design of Existing Code ? Well, we learn that without tests, you can't refactor. Well, you can - it's really not wise to do so, however. It will be difficult to know if you've broken something or slightly altered a particular functionality.

Of course, tests also help you prove what you've got is a set of modules that performs to their specifications - or in the absense of a specification - proving that the code does what it looks like it's supposed to do based on certain circumstance.

Given that our codebase is huge, undocumented, and more important untested, I've come up with a few snippets of shell code to really move me pretty far forward with my task.

First, to create a directory hierarchy to house all my new tests:

for i in $(find . -name "*.pm")
  do touch $(echo $i | \
           sed -e 's/\./\/path\/to\/dir/' | \
           sed -e 's/\.pm$/.t/')
done

And to give the files some default content (it's ugly but it sorta works, YMMV):

for i in $(find . -size 0)
  do echo '#!/usr/bin/perl' >> $i
    echo "" >> $i
    echo "use strict;" >> $i
    echo "use warnings;" >> $i
    echo "" >> $i
    echo "Test::More 'no_plan';" >> $i
    echo "" >> $i
    echo "use_ok( '`sed -e 's/\//::/' | \
      sed -e 's/\.t//'`' );" >> $i
  done

These snippets, plus my previously mentioned vim tip are really getting me pretty fair along in creating a comprehensive test suite and a good set of documentation for all of our legacy code.

Oh, and as a side benefit, I'm getting to know the modules pretty well while I'm at it :)

I'm going through a lot of legacy code lately, and got tired of manually opening up the first legacy file I documented (to make sure I was following the same standard I had implemented - it's not quite in my long term memory just yet), scrolling through the tedious documentation, copying (or retyping(!)) the text into the file I was working on, etc.

So, I decided to write a quick little mapping for that menial task.

First step is to create a template for the POD I want to insert:

__END__

=NAME

=SYNOPSIS

=DESCRIPTION

...

And then this helpful mapping in my ~/.vimrc

" Automatically add a POD template
" to the end of a file
noremap ,ap maG:r ~/podtemplate<cr>'a

Mnemonic: Add Pod.

... which is at least smart enough to set a mark at your current position, move to the end of the file, insert the contents of ~/podtemplate, and return to your saved position. Caveats: It's NOT smart enough to know if you've already set an 'a' mark, and it's NOT smart enough to NOT insert the template if there's already POD in the file.