 = rails_rcov plugin for Rails

rails_rcov provides easy-to-use Rake tasks to determine the code coverage of
your unit, functional, and integration tests using Mauricio Fernandez's rcov
tool.

== Installation

First, install rcov from Mauricio's web site
[http://eigenclass.org/hiki.rb?rcov]. Make sure it's on your system path, so
that typing +rcov+ on the command line actually runs it. THIS PLUGIN DOESN'T DO
ANYTHING BESIDES GENERATE ERRORS UNLESS YOU INSTALL RCOV FIRST. RCOV CONTAINS
ALL THE MAGIC, THIS PLUGIN JUST RUNS IT.

Second, install this plugin. If your project is source-controlled by Subversion
(which it should be, really), the easiest way to install this is via Rails'
plugin script:

  ./script/plugin install -x http://svn.codahale.com/rails_rcov

If you're not using Subversion, or if you don't want it adding
<tt>svn:externals</tt> in your project, remove the <tt>-x</tt> switch:

  ./script/plugin install http://svn.codahale.com/rails_rcov

== Usage

For each <tt>test:blah</tt> task you have for your Rails project, rails_rcov
adds two more: <tt>test:blah:rcov</tt> and <tt>test:blah:clobber_rcov</tt>.

Running <tt>rake test:units:rcov</tt>, for example, will run your unit tests
through rcov and write the code coverage reports to
<tt>your_rails_app/coverage/units</tt>.

Running <tt>test:units:clobber_rcov</tt> will erase the generated report for the
unit tests.

Each rcov task takes two optional parameters: RCOV_PARAMS, whose argument is
passed along to rcov, and SHOW_ONLY, which limits the files displayed in the
report.

RCOV_PARAMS:
  # sort by coverage
  rake test:units:rcov RCOV_PARAMS="--sort=coverage"

  # show callsites and hide fully covered files
  rake test:units:rcov RCOV_PARAMS="--callsites --only-uncovered"

Check the rcov documentation for more details.

SHOW_ONLY is a comma-separated list of the files you'd like to see. Right now
there are four types of files rake_rcov recognizes: models, helpers,
controllers, and lib. These can be abbreviated to their first letters:

  # only show files from app/models
  rake test:units:rcov SHOW_ONLY=models
  
  # only show files from app/helpers and app/controllers
  rake test:units:rcov SHOW_ONLY=helpers,controllers
  
  # only show files from app/helpers and app/controllers, with less typing
  rake test:units:rcov SHOW_ONLY=h,c

Please note that rails_rcov has only been tested with a Bash shell, and any
other environment could well explode in your face. If you're having trouble
getting this to work on Windows, please take the time to figure out what's not
working. Most of the time it boils down to the different ways the Window shell
and the Bash shell escape metacharacters. Play around with the way rcov_rake
escapes data (like on line 73, or 78) and send me a fix. I don't have a working
Windows environment anymore, so leaving it up to me won't solve anything. ;-)

== Resources

=== Subversion

* http://svn.codahale.com/rails_rcov

=== Blog

* http://blog.codahale.com

== Credits

Written by Coda Hale <coda.hale@gmail.com>. Thanks to Nils Franzen for a Win32
escaping patch. Thanks to Alex Wayne for suggesting how to make SHOW_ONLY not be
useless.