NOTE: I created 'interact' before I discovered Test::Continuous 'autoprove' (https://metacpan.org/module/autoprove).  
'autoprove' is more complete, so I recommend using it for Perl development.  
There are still uses for 'interact' since it can be used for things other than Perl development.

'interact' watches for any changes in a directory
and then runs a command (such as run your unit test suite)
and outputs the results either to the terminal or to growl

How to use:
1. install 'interact' somewhere in your path
2. run 'interact' before you start developing and it will do its magic
3. pass in options to 'interact' as you see fit