Example setup to test a gem or plugin against rails 2 and 3:
Version 1
# Gemfile gem 'activerecord', ENV['AR'] # Rakefile task :default do sh "rspec spec" end task :all do sh "AR=2.3.14 && (bundle || bundle install) && bundle exec rake" sh "AR=3.0.10 && (bundle || bundle install) && bundle exec rake" sh "AR=3.1.1 && (bundle || bundle install) && bundle exec rake" end
Version 2 (if 1 is not possible…)
# Gemfile ... gem 'rails', '~>3' # spec/rails2/Gemfile ... gem 'rails', '~>2' # Rakefile task :spec do sh "bundle exec rspec spec" end task :rails2 do sh "cd spec/rails2 && bundle exec rspec ../../spec" end task :default do sh "rake spec && rake rails2" end