Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
If you've ever automated any operations with Perl you'll most likely have written a small script or two, and then left them to run. But how do you know that your code is correct? The answer is to write some test cases and verify they perform correctly. With Perls test facilities this is a simple thing to do.
Most large Perl projects have a test suite, and so do many of the common modules you'll have installed.
To get started we'll look at a simple example. Suppose your script uses some non-standard Perl modules that suggests the very first test you write should verify that those are available. That way if you attempt to run the program upon a new host you'll immediately know whether you need to install these non-standard modules.