From be2ff202a3b53e32b32b9f83feac972c43754723 Mon Sep 17 00:00:00 2001
From: Edward Tsech <edtsech@gmail.com>
Date: Sat, 23 Jul 2011 01:54:03 +0700
Subject: [PATCH] #74: Changed method_defined? to column_names.include? & Fix
 test for case without object_changes column

---
 lib/paper_trail/has_paper_trail.rb | 2 +-
 lib/paper_trail/version.rb         | 2 +-
 test/test_helper.rb                | 8 --------
 test/unit/model_test.rb            | 9 +++------
 4 files changed, 5 insertions(+), 16 deletions(-)

diff --git a/lib/paper_trail/has_paper_trail.rb b/lib/paper_trail/has_paper_trail.rb
index 931ef71e..3ea50117 100644
--- a/lib/paper_trail/has_paper_trail.rb
+++ b/lib/paper_trail/has_paper_trail.rb
@@ -114,7 +114,7 @@ module PaperTrail
             :object    => object_to_string(item_before_change),
             :whodunnit => PaperTrail.whodunnit
           }
-          if Version.method_defined? :object_changes
+          if self.class.version_class_name.constantize.column_names.include?('object_changes')
             # The double negative (reject, !include?) preserves the hash structure of self.changes.
             data[:object_changes] = self.changes.reject do |key, value|
               !notably_changed.include?(key)
diff --git a/lib/paper_trail/version.rb b/lib/paper_trail/version.rb
index 465bc7b1..86b6166a 100644
--- a/lib/paper_trail/version.rb
+++ b/lib/paper_trail/version.rb
@@ -82,7 +82,7 @@ class Version < ActiveRecord::Base
   # Returns what changed in this version of the item.  Cf. `ActiveModel::Dirty#changes`.
   # Returns nil if your `versions` table does not have an `object_changes` text column.
   def changeset
-    if Version.method_defined?(:object_changes)
+    if self.class.column_names.include?('object_changes')
       if changes = object_changes
         YAML::load(changes)
       else
diff --git a/test/test_helper.rb b/test/test_helper.rb
index bcdcd364..c4099b65 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -47,11 +47,3 @@ def change_schema
   end
   ActiveRecord::Migration.verbose = true
 end
-
-def remove_object_changes_column
-  ActiveRecord::Migration.verbose = false
-  ActiveRecord::Schema.define do
-    remove_column :versions, :object_changes
-  end
-  ActiveRecord::Migration.verbose = true
-end
diff --git a/test/unit/model_test.rb b/test/unit/model_test.rb
index 23fc6c5c..b21483a3 100644
--- a/test/unit/model_test.rb
+++ b/test/unit/model_test.rb
@@ -109,12 +109,6 @@ class HasPaperTrailModelTest < ActiveSupport::TestCase
           assert_equal ({'name' => ['Henry', 'Harry']}), @widget.versions.last.changeset
         end
 
-        should "not have stored changes if object_changes column doesn't exist" do
-          remove_object_changes_column
-          Version.reset_column_information
-          assert_nil @widget.versions.last.changeset
-        end
-
         if defined?(ActiveRecord::IdentityMap) && ActiveRecord::IdentityMap.respond_to?(:without)
           should 'not clobber the IdentityMap when reifying' do
             module ActiveRecord::IdentityMap
@@ -786,6 +780,9 @@ class HasPaperTrailModelTest < ActiveSupport::TestCase
       setup { @post.update_attributes({ :content => "Some new content" }) }
       should_change('the number of post versions') { PostVersion.count }
       should_not_change('the number of versions') { Version.count }
+      should "not have stored changes when object_changes column doesn't exist" do
+        assert_nil @post.versions.last.changeset
+      end
     end
   end