On Teardown Restore schema to previous state.

test/test_helper.rb

@@ -33,3 +33,12 @@ def change_schema
   end
   ActiveRecord::Migration.verbose = true
 end
+
+def restore_schema
+  ActiveRecord::Migration.verbose = false
+  ActiveRecord::Schema.define do
+    add_column :widgets, :sacrificial_column, :string
+    remove_column :versions, :custom_created_at
+  end
+  ActiveRecord::Migration.verbose = true
+end

test/unit/model_test.rb

@@ -437,6 +437,10 @@ class HasPaperTrailModelTest < ActiveSupport::TestCase
         @last = @widget.versions.last
       end
 
+      teardown do 
+        restore_schema
+      end
+
       should 'reify previous version' do
         assert_kind_of Widget, @last.reify
       end

test/unit/timestamp_test.rb

@@ -19,6 +19,7 @@ class TimestampTest < ActiveSupport::TestCase
 
   teardown do
     PaperTrail.timestamp_field = :created_at
+    restore_schema
   end
 
   test 'versions works with custom timestamp field' do

test/unit/version_test.rb

@@ -7,6 +7,12 @@ class PaperTrail::VersionTest < ActiveSupport::TestCase
     assert PaperTrail::Version.creates.present?
   end
 
+  teardown do
+    restore_schema
+    Animal.connection.schema_cache.clear!
+    Animal.reset_column_information
+  end
+
   context "PaperTrail::Version.creates" do
     should "return only create events" do
       PaperTrail::Version.creates.each do |version|