for generating coverage with rspec 2 in ruby 1.9.2 using Simplecov

coverage.rake

Rake.application.instance_variable_get('@tasks').delete('spec:rcov')

module SimpleCov
  class RakeTask < ::Rake::TaskLib

    def initialize(*args)
      desc "Run RSpec code examples"
      task(args.shift || :simplecov) do
        RakeFileUtils.send(:verbose, true) do
          if files_to_run.empty?
            puts "No examples matching #{pattern} could be found"
          else
            begin
              ruby(spec_command_with_simplecov)
            rescue
              raise("ruby #{spec_command_with_simplecov} failed")
            end
          end
        end
      end
    end

  private

    def files_to_run # :nodoc:
      if ENV['SPEC']
        FileList[ ENV['SPEC'] ]
      else
        FileList[ './spec/**/*_spec.rb' ].map { |f| %["#{f}"] }
      end
    end

    def spec_command_with_simplecov
      cmd_parts = []
      cmd_parts << "-S"
      cmd_parts << "bundle exec"
      cmd_parts << 'script/simplecov'
      cmd_parts << files_to_run
      cmd_parts.flatten.compact.reject(&blank).join(" ")
    end

    def blank
      lambda {|s| s == ""}
    end
  end
end

namespace :spec do
  SimpleCov::RakeTask.new(:coverage => 'db:test:prepare')
end

simplecov

#!/usr/bin/env ruby

# put this in your rails app script directory and make it executable

require 'rspec/core'
require 'simplecov'

module RSpec
  module Core
    class Runner

      def self.autorun_with_simplecov
        return if autorun_disabled? || installed_at_exit? || running_in_drb?
        @installed_at_exit = true
        at_exit { run_with_simplecov(ARGV, $stderr, $stdout) ? exit(0) : exit(1) }
      end

      def self.run_with_simplecov(args, err, out)
        SimpleCov.use_merging false
        SimpleCov.start do
          add_filter "/autotest/"
          add_filter "/config/"
          add_filter "/db/"
          add_filter "/fixtures/"
          add_filter "/lib/"
          add_filter "/script/"
          add_filter "/spec/"
          add_filter "/vendor/"

          add_group 'Controllers',  'app/controllers'
          add_group 'Models',       'app/models'
          add_group 'Helpers',      'app/helpers'
          add_group 'Mailers',      'app/mailers'
          add_group 'Observers',    'app/observers'
        end

        run(args, err, out)
      end
    end
  end
end

RSpec::Core::Runner.autorun_with_simplecov