Musings of a Trained Monkey

There is an interesting thread going on the rails-core mailing list about testing coverage and documentation. I learned about rcov which provides testing coverage metrics for Ruby applications. Here are links to the results so farTook this content down due to it being stale:

• ActionMailer
  rcov -x activerecord,activesupport,actionpack test/*.rb
• ActionPack(top level only)
  rcov -x activerecord,activesupport,actionmailer test/*.rb
• ActionWebService
  rcov -x activerecord,activesupport,actionpack,actionmailer test/*.rb

I modified rcov a bit trying to get it to work covering the Rails codebase. The results were somewhat mixed, but only railties blew up strictly in rcov with a SystemStackError. Showing the complete test coverage of ActiveRecord in particular will present a challenge due to the number of database connectors it has.

As an example of differences between running rake test versus rcov test*.rb, in Activerecord there is a test case named aaa_create_tables_test that runs fine with rake, but with rcov there is a load error because aaa_create_tables_test requires abstract_unit.rb which simple test/*.rb has loaded yet because aaa_create_tables_test comes before abstract_unit. I have gotten farther with loading abstract_unit.rb explicitly rcov -x actionpack,activesupport test/abstract_unit.rb test/*.rb but it would be better if I could figure out how to wrap rake inside of rcov...