Only run tests for ActiveRecord::Enum when it is defined

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 3.0.3 (Unreleased)
 
-  - [#373](https://github.com/airblade/paper_trail/pull/373) - Fix default sort order for the `versions` association in Rails `4.1`
+  - [#383](https://github.com/airblade/paper_trail/pull/383) - Make gem compatible with `ActiveRecord::Enum` (available in `ActiveRecord` 4.1+).
+  - [#373](https://github.com/airblade/paper_trail/pull/373) - Fix default sort order for the `versions` association in Rails `4.1`.
   - [#372](https://github.com/airblade/paper_trail/pull/372) - Use [Arel](https://github.com/rails/arel) for SQL construction.
   - [#347](https://github.com/airblade/paper_trail/pull/347) - Autoload `ActiveRecord` models in via a `Rails::Engine` when
     the gem is used with `Rails`.

lib/paper_trail/has_paper_trail.rb

@@ -345,10 +345,10 @@ module PaperTrail
         enums = previous.respond_to?(:defined_enums) ? previous.defined_enums : {}
         previous.tap do |prev|
           prev.id = id # `dup` clears the `id` so we add that back
-          changed_attributes.select { |k,v| self.class.column_names.include?(k) }.each { |attr, before|
-            before = enums[attr][before] unless enums[attr].nil?
+          changed_attributes.select { |k,v| self.class.column_names.include?(k) }.each do |attr, before|
+            before = enums[attr][before] if enums[attr]
             prev[attr] = before
-          }
+          end
         end
       end
 

spec/models/post_with_status_spec.rb

@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+# This model is in the test suite soley for the purpose of testing ActiveRecord::Enum,
+# which is available in ActiveRecord4+ only
+describe PostWithStatus do
+  if defined?(ActiveRecord::Enum)
+    with_versioning do
+      let(:post) { PostWithStatus.create!(:status => 'draft') }
+
+      it "should stash the enum value properly in versions" do
+        post.published!
+        post.archived!
+        post.previous_version.published?.should == true
+      end
+    end
+  end
+end

test/dummy/app/models/post_with_status.rb

@@ -1,4 +1,8 @@
 class PostWithStatus < ActiveRecord::Base
   has_paper_trail
-  enum status: { draft: 0, published: 1, archived: 2 }
+
+  # ActiveRecord::Enum is only supported in AR4.1+
+  if defined?(ActiveRecord::Enum)
+    enum status: { draft: 0, published: 1, archived: 2 }
+  end
 end

test/unit/model_test.rb

@@ -1376,17 +1376,6 @@ class HasPaperTrailModelTest < ActiveSupport::TestCase
     end
   end
 
-  context 'A record with enum fields' do
-    should "keep the integer in versions" do
-      post = PostWithStatus.create!(status: "draft")
-      assert post.draft?
-      post.published!
-      post.archived!
-      assert post.previous_version.published?
-    end
-  end
-
-
   private
 
   # Updates `model`'s last version so it looks like the version was