Added Gemfiles and start using Appraisal

Appraisals

+appraise "rails2" do
+  gem "rails", "~>2.3.0"
+end
+
+appraise "rails3" do
+  gem "rails", "~>3.0.0"
+end
+

Gemfile

+source "http://rubygems.org"
+gem "shoulda"
+gem "mocha"
+gem "rake"
+gem "ruby-debug"
+gem "aws-s3", :require => "aws/s3"
+gem "sqlite3-ruby", "~>1.3.0"

Gemfile.lock

+GEM
+  remote: http://rubygems.org/
+  specs:
+    aws-s3 (0.6.2)
+      builder
+      mime-types
+      xml-simple
+    builder (3.0.0)
+    columnize (0.3.2)
+    linecache (0.43)
+    mime-types (1.16)
+    mocha (0.9.9)
+      rake
+    rake (0.8.7)
+    ruby-debug (0.10.4)
+      columnize (>= 0.1)
+      ruby-debug-base (~> 0.10.4.0)
+    ruby-debug-base (0.10.4)
+      linecache (>= 0.3)
+    shoulda (2.11.3)
+    sqlite3-ruby (1.3.2)
+    xml-simple (1.0.12)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  aws-s3
+  mocha
+  rake
+  ruby-debug
+  shoulda
+  sqlite3-ruby (~> 1.3.0)

Rakefile

+require 'rubygems'
+require 'appraisal'
+require 'bundler/setup'
+
 require 'rake'
 require 'rake/testtask'
 require 'rake/rdoctask'

gemfiles/rails2.gemfile

+# This file was generated by Appraisal
+
+source "http://rubygems.org"
+gem "ruby-debug"
+gem "rails", "~>2.3.0"
+gem "rake"
+gem "sqlite3-ruby", "~>1.3.0"
+gem "shoulda"
+gem "mocha"
+gem "aws-s3", {:require=>"aws/s3"}
\ No newline at end of file

gemfiles/rails2.gemfile.lock

+GEM
+  remote: http://rubygems.org/
+  specs:
+    actionmailer (2.3.10)
+      actionpack (= 2.3.10)
+    actionpack (2.3.10)
+      activesupport (= 2.3.10)
+      rack (~> 1.1.0)
+    activerecord (2.3.10)
+      activesupport (= 2.3.10)
+    activeresource (2.3.10)
+      activesupport (= 2.3.10)
+    activesupport (2.3.10)
+    aws-s3 (0.6.2)
+      builder
+      mime-types
+      xml-simple
+    builder (3.0.0)
+    columnize (0.3.2)
+    linecache (0.43)
+    mime-types (1.16)
+    mocha (0.9.9)
+      rake
+    rack (1.1.0)
+    rails (2.3.10)
+      actionmailer (= 2.3.10)
+      actionpack (= 2.3.10)
+      activerecord (= 2.3.10)
+      activeresource (= 2.3.10)
+      activesupport (= 2.3.10)
+      rake (>= 0.8.3)
+    rake (0.8.7)
+    ruby-debug (0.10.4)
+      columnize (>= 0.1)
+      ruby-debug-base (~> 0.10.4.0)
+    ruby-debug-base (0.10.4)
+      linecache (>= 0.3)
+    shoulda (2.11.3)
+    sqlite3-ruby (1.3.2)
+    xml-simple (1.0.12)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  aws-s3
+  mocha
+  rails (~> 2.3.0)
+  rake
+  ruby-debug
+  shoulda
+  sqlite3-ruby (~> 1.3.0)

gemfiles/rails3.gemfile

+# This file was generated by Appraisal
+
+source "http://rubygems.org"
+gem "ruby-debug"
+gem "rails", "~>3.0.0"
+gem "rake"
+gem "sqlite3-ruby", "~>1.3.0"
+gem "shoulda"
+gem "mocha"
+gem "aws-s3", {:require=>"aws/s3"}
\ No newline at end of file

gemfiles/rails3.gemfile.lock

+GEM
+  remote: http://rubygems.org/
+  specs:
+    abstract (1.0.0)
+    actionmailer (3.0.3)
+      actionpack (= 3.0.3)
+      mail (~> 2.2.9)
+    actionpack (3.0.3)
+      activemodel (= 3.0.3)
+      activesupport (= 3.0.3)
+      builder (~> 2.1.2)
+      erubis (~> 2.6.6)
+      i18n (~> 0.4)
+      rack (~> 1.2.1)
+      rack-mount (~> 0.6.13)
+      rack-test (~> 0.5.6)
+      tzinfo (~> 0.3.23)
+    activemodel (3.0.3)
+      activesupport (= 3.0.3)
+      builder (~> 2.1.2)
+      i18n (~> 0.4)
+    activerecord (3.0.3)
+      activemodel (= 3.0.3)
+      activesupport (= 3.0.3)
+      arel (~> 2.0.2)
+      tzinfo (~> 0.3.23)
+    activeresource (3.0.3)
+      activemodel (= 3.0.3)
+      activesupport (= 3.0.3)
+    activesupport (3.0.3)
+    arel (2.0.4)
+    aws-s3 (0.6.2)
+      builder
+      mime-types
+      xml-simple
+    builder (2.1.2)
+    columnize (0.3.2)
+    erubis (2.6.6)
+      abstract (>= 1.0.0)
+    i18n (0.4.2)
+    linecache (0.43)
+    mail (2.2.10)
+      activesupport (>= 2.3.6)
+      i18n (~> 0.4.1)
+      mime-types (~> 1.16)
+      treetop (~> 1.4.8)
+    mime-types (1.16)
+    mocha (0.9.9)
+      rake
+    polyglot (0.3.1)
+    rack (1.2.1)
+    rack-mount (0.6.13)
+      rack (>= 1.0.0)
+    rack-test (0.5.6)
+      rack (>= 1.0)
+    rails (3.0.3)
+      actionmailer (= 3.0.3)
+      actionpack (= 3.0.3)
+      activerecord (= 3.0.3)
+      activeresource (= 3.0.3)
+      activesupport (= 3.0.3)
+      bundler (~> 1.0)
+      railties (= 3.0.3)
+    railties (3.0.3)
+      actionpack (= 3.0.3)
+      activesupport (= 3.0.3)
+      rake (>= 0.8.7)
+      thor (~> 0.14.4)
+    rake (0.8.7)
+    ruby-debug (0.10.4)
+      columnize (>= 0.1)
+      ruby-debug-base (~> 0.10.4.0)
+    ruby-debug-base (0.10.4)
+      linecache (>= 0.3)
+    shoulda (2.11.3)
+    sqlite3-ruby (1.3.2)
+    thor (0.14.6)
+    treetop (1.4.9)
+      polyglot (>= 0.3.1)
+    tzinfo (0.3.23)
+    xml-simple (1.0.12)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  aws-s3
+  mocha
+  rails (~> 3.0.0)
+  rake
+  ruby-debug
+  shoulda
+  sqlite3-ruby (~> 1.3.0)

paperclip.gemspec

@@ -28,6 +28,7 @@ spec = Gem::Specification.new do |s|
   s.add_dependency 'activerecord'
   s.add_dependency 'activesupport'
   s.add_development_dependency 'shoulda'
+  s.add_development_dependency 'appraisal'
   s.add_development_dependency 'mocha'
   s.add_development_dependency 'aws-s3'
   s.add_development_dependency 'sqlite3-ruby'

test/helper.rb

@@ -5,18 +5,6 @@ require 'test/unit'
 require 'shoulda'
 require 'mocha'
 
-case ENV['RAILS_VERSION']
-when '2.1' then
-  gem 'activerecord',  '~>2.1.0'
-  gem 'activesupport', '~>2.1.0'
-when '3.0' then
-  gem 'activerecord',  '~>3.0.0'
-  gem 'activesupport', '~>3.0.0'
-else
-  gem 'activerecord',  '~>2.3.0'
-  gem 'activesupport', '~>2.3.0'
-end
-
 require 'active_record'
 require 'active_record/version'
 require 'active_support'