Among the things that make me ga-ga for Ruby testing libraries is the ZenTest gem, which includes a super handy utility called 'autotest'. Autotest is meant to be run from the top of your project directory and it will search through your
/test directory and run all test files it finds there (and report passes/failures on the console). My own development preference is writing specifications for my software using RSpec, which includes a tiny utility script called 'autospec' that enables 'autotest' to run anything it finds under the
/spec directory of your project environment. As well, setting an environment variable called
AUTOFEATURE=true tells autotest to search through your
/features directory and run all your Cucumber features after file-system changes (this capability is added by Cucumber and not actually part of the ZenTest gem).
I have been running autospec nonstop as I tinker with a Sinatra app I have been writing. The normal behavior for autospec is that it runs all specs & features and then stops, watching the filesystem for any file changes that trigger it to run specs again. Recently, though, I noticed that the specs would start running and then go into an infinite loop of running and running and running... At first I thought that I'd updated a gem in the vendor directory of my Sinatra app that broke autospec somehow. After doing a lot of tinkering, I tracked it down to a Webrat log file that gets updated each time my Cucumber specs make it all the way through the login feature of my web app.
Autotest includes a configuration capability that lets you specify which file updates it should ignore (i.e. which files can be updated without triggering an execution of all the specs for your project). These exceptions can be declared in a
.autotest file that needs to reside in the home directory of your development environment. I think I have covered all the bases for things that I want to keep from triggering my autospec runs. Here is what my file looks like:
The 'autotest/growl' require is so that I can see growl popups when my specs pass or fail. The gem for this is 'autotest-growl'.
UPDATE - 12/28/09: The 'autotest' script supports a '-v' flag which will cause it to report what file it saw changed to trigger your last test run. I only learned about this flag thanks to a comment on this original post by the great Ryan Davis.