Make the build more friendly.

(cherry picked from commit f58f73210621261c214136eb7514be459032ee0f)

lib/paperclip/storage.rb

@@ -127,7 +127,13 @@ module Paperclip
     #   separate parts of your file name.
     module S3
       def self.extended base
+        begin
           require 'aws/s3'
+        rescue LoadError => e
+          e.message << " (You may need to install the aws-s3 gem)"
+          raise e
+        end
+
         base.instance_eval do
           @s3_credentials = parse_credentials(@options[:s3_credentials])
           @bucket         = @options[:bucket]         || @s3_credentials[:bucket]

test/helper.rb

 require 'rubygems'
 require 'test/unit'
 require 'shoulda'
-require 'mocha'
 require 'tempfile'
 
+gem 'jferris-mocha', '0.9.5.0.1241126838'
+require 'mocha'
+
 gem 'sqlite3-ruby'
 
 require 'active_record'
@@ -97,3 +99,10 @@ end
 def attachment options
   Paperclip::Attachment.new(:avatar, FakeModel.new, options)
 end
+
+def silence_warnings
+  old_verbose, $VERBOSE = $VERBOSE, nil
+  yield
+ensure
+  $VERBOSE = old_verbose
+end

test/interpolations_test.rb

@@ -7,7 +7,7 @@ class InterpolationsTest < Test::Unit::TestCase
     assert ! methods.include?(:[]=)
     assert ! methods.include?(:all)
     methods.each do |m|
-      assert Paperclip::Interpolations.respond_to? m
+      assert Paperclip::Interpolations.respond_to?(m)
     end
   end
 

test/storage_test.rb

 require 'test/helper'
+require 'aws/s3'
 
 class StorageTest < Test::Unit::TestCase
+  def rails_env(env)
+    silence_warnings do
+      Object.const_set(:RAILS_ENV, env)
+    end
+  end
+
   context "Parsing S3 credentials" do
     setup do
       AWS::S3::Base.stubs(:establish_connection!)
@@ -15,25 +22,25 @@ class StorageTest < Test::Unit::TestCase
     end
 
     teardown do
-      Object.const_set("RAILS_ENV", @current_env)
+      rails_env(@current_env)
     end
 
     should "get the correct credentials when RAILS_ENV is production" do
-      Object.const_set('RAILS_ENV', "production")
+      rails_env("production")
       assert_equal({:key => "12345"},
                    @avatar.parse_credentials('production' => {:key => '12345'},
                                              :development => {:key => "54321"}))
     end
 
     should "get the correct credentials when RAILS_ENV is development" do
-      Object.const_set('RAILS_ENV', "development")
+      rails_env("development")
       assert_equal({:key => "54321"},
                    @avatar.parse_credentials('production' => {:key => '12345'},
                                              :development => {:key => "54321"}))
     end
 
     should "return the argument if the key does not exist" do
-      Object.const_set('RAILS_ENV', "not really an env")
+      rails_env("not really an env")
       assert_equal({:test => "12345"}, @avatar.parse_credentials(:test => "12345"))
     end
   end
@@ -102,15 +109,15 @@ class StorageTest < Test::Unit::TestCase
       @old_env = RAILS_ENV
     end
 
-    teardown{ Object.const_set("RAILS_ENV", @old_env) }
+    teardown{ rails_env(@old_env) }
 
     should "get the right bucket in production" do
-      Object.const_set("RAILS_ENV", "production")
+      rails_env("production")
       assert_equal "prod_bucket", @dummy.avatar.bucket_name
     end
 
     should "get the right bucket in development" do
-      Object.const_set("RAILS_ENV", "development")
+      rails_env("development")
       assert_equal "dev_bucket", @dummy.avatar.bucket_name
     end
   end