add a test/run_all script

README.textile

@@ -64,8 +64,12 @@ h2. Tests
 You can run tests both with
 
 * `rake test` or just `rake`
-* run any test file directly, e.g. `ruby -Itest test/api/simple_test.rb`
-* run all tests with `ruby -Itest test/all.rb`
+* run any test file directly, e.g. `ruby -Ilib -Itest test/api/simple_test.rb`
+* run all tests with `ruby -Ilib -Itest test/all.rb`
+
+You can run all tests against all Gemfiles with
+
+* `ruby test/run_all.rb`
 
 The structure of the test suite is a bit unusual as it uses modules to reuse
 particular tests in different test cases.

ci/Gemfile.no-rails.lock

@@ -0,0 +1,17 @@
+GEM
+  remote: http://rubygems.org/
+  specs:
+    mocha (0.9.9)
+      rake
+    rake (0.8.7)
+    test_declarative (0.0.4)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  mocha
+  test_declarative
+
+METADATA
+  version: 1.0.6

test/run_all.rb

@@ -0,0 +1,21 @@
+def bundle_check
+  `bundle check` == "The Gemfile's dependencies are satisfied\n"
+end
+
+command  = 'ruby -w -Ilib -Itest test/all.rb'
+gemfiles = %w(ci/Gemfile.all ci/Gemfile.rails-3.x ci/Gemfile.rails-2.3.x ci/Gemfile.no-rails)
+
+results = gemfiles.map do |gemfile|
+  puts "BUNDLE_GEMFILE=#{gemfile}"
+  ENV['BUNDLE_GEMFILE'] = gemfile
+
+  unless bundle_check
+    puts "bundle install"
+    system('bundle install')
+  end
+
+  puts command
+  system('ruby -w -Ilib -Itest test/all.rb')
+end
+
+exit(results.inject(true) { |a, b| a && b })