Install thoughtbot shoulda and rcov (the right way)

By kenglish

Install rcov & ruby-prof (rcov-0.9.6 & ruby-prof-0.7.3 at the time of this writing).

sudo gem install ruby-prof rcov --no-ri --no-rdoc

Update your test/test_helper.rb, add:

require 'shoulda/rails'

Install Thoughbot’s Shoulda gem (shoulda-2.10.2 at the time of this writing). Make sure you have added GemCutter as one of your ruby gem sources.

sudo gem install shoulda --no-ri --no-rdoc

Edit your applicaitons main Rakefile and add:

require(File.join(File.dirname(__FILE__), 'config', 'boot'))
require 'rake'
require 'rake/testtask'
require 'rake/rdoctask'
require 'tasks/rails'
require 'shoulda/tasks'
 
def run_coverage(files)
  rm_f "coverage"
  rm_f "coverage.data"
 
  # turn the files we want to run into a  string
  if files.length == 0
    puts "No files were specified for testing"
    return
  end
 
  files = files.join(" ")
 
  if PLATFORM =~ /darwin/
    exclude = '--exclude "gems/*"'
  else
    exclude = '--exclude "rubygems/*"'
  end
 
  rcov = "rcov --rails -Ilib:test --sort coverage --text-report #{exclude}  --aggregate coverage.data"
  cmd = "#{rcov} #{files}"
  puts cmd
  sh cmd
end
namespace :test do
 
  desc "Measures unit, functional, and integration test coverage"
  task :coverage do
    run_coverage Dir["test/**/*.rb"]
  end
 
  namespace :coverage do
    desc "Runs coverage on unit tests"
    task :units do
      run_coverage Dir["test/unit/**/*.rb"]
    end
    desc "Runs coverage on functional tests"
    task :functionals do
      run_coverage Dir["test/functional/**/*.rb"]
    end
    desc "Runs coverage on integration tests"
    task :integration do
      run_coverage Dir["test/integration/**/*.rb"]
    end
  end
end

Checkout your new coverage rake tasks:

rake -T | grep cov

Should show you:

rake test:coverage                        # Measures unit, functional, and integration test coverage
rake test:coverage:functionals            # Runs coverage on functional tests
rake test:coverage:integration            # Runs coverage on integration tests
rake test:coverage:units                  # Runs coverage on unit tests