Fix test so it fails when the code is wrong ;)

test/dummy/app/models/animal.rb

@@ -1,3 +1,4 @@
 class Animal < ActiveRecord::Base
   has_paper_trail
+  set_inheritance_column 'species'
 end

test/dummy/app/models/cat.rb

@@ -1,3 +1,2 @@
 class Cat < Animal
-  set_inheritance_column 'species'
 end

test/dummy/app/models/dog.rb

@@ -1,3 +1,2 @@
 class Dog < Animal
-  set_inheritance_column 'species'
 end

test/unit/inheritance_column_test.rb

@@ -7,25 +7,36 @@ class InheritanceColumnTest < ActiveSupport::TestCase
       @animal = Animal.create :name => 'Animal'
       @animal.update_attributes :name => 'Animal from the Muppets'
       @animal.update_attributes :name => 'Animal Muppet'
+      @animal.destroy
 
       @dog = Dog.create :name => 'Snoopy'
       @dog.update_attributes :name => 'Scooby'
       @dog.update_attributes :name => 'Scooby Doo'
+      @dog.destroy
 
       @cat = Cat.create :name => 'Garfield'
       @cat.update_attributes :name => 'Garfield (I hate Mondays)'
       @cat.update_attributes :name => 'Garfield The Cat'
+      @cat.destroy
     end
 
     should 'work with custom STI inheritance column' do
-      assert_equal 9, Version.count
-      assert_equal 3, @animal.versions.count
-      assert_equal 3, @dog.versions.count
-      assert_equal 3, @cat.versions.count
+      assert_equal 12, Version.count
+      assert_equal 4, @animal.versions.count
+      assert @animal.versions.first.reify.nil?
+      @animal.versions[1..-1].each { |v| assert_equal 'Animal', v.reify.class.name }
 
-      assert_equal 'Animal from the Muppets',   @animal.versions.last.reify.name
-      assert_equal 'Scooby',       @dog.versions.last.reify.name
-      assert_equal 'Garfield (I hate Mondays)', @cat.versions.last.reify.name
+      # For some reason `@dog.versions` doesn't include the final `destroy` version.
+      # Neither do `@dog.versions.scoped` nor `@dog.versions(true)` nor `@dog.versions.reload`.
+      dog_versions = Version.where(:item_id => @dog.id)
+      assert_equal 4, dog_versions.count
+      assert dog_versions.first.reify.nil?
+      dog_versions[1..-1].each { |v| assert_equal 'Dog', v.reify.class.name }
+
+      cat_versions = Version.where(:item_id => @cat.id)
+      assert_equal 4, cat_versions.count
+      assert cat_versions.first.reify.nil?
+      cat_versions[1..-1].each { |v| assert_equal 'Cat', v.reify.class.name }
     end
   end