:versions association should default to sorting by the VersionConcern#timestamp_order method to match the scope methods

lib/paper_trail/has_paper_trail.rb

@@ -61,13 +61,13 @@ module PaperTrail
 
         if ::ActiveRecord::VERSION::MAJOR >= 4 # `has_many` syntax for specifying order uses a lambda in Rails 4
           has_many self.versions_association_name,
-            lambda { order("#{PaperTrail.timestamp_field} ASC") },
+            lambda { |model| order(model.version_class_name.constantize.timestamp_sort_order) },
             :class_name => self.version_class_name, :as => :item
         else
           has_many self.versions_association_name,
             :class_name => self.version_class_name,
             :as         => :item,
-            :order      => "#{PaperTrail.timestamp_field} ASC"
+            :order      => self.paper_trail_version_class.timestamp_sort_order
         end
 
         options_on = Array(options[:on]) # so that a single symbol can be passed in without wrapping it in an `Array`

lib/paper_trail/version_concern.rb

@@ -41,8 +41,7 @@ module PaperTrail
         end
 
         obj = obj.send(PaperTrail.timestamp_field) if obj.is_a?(self)
-        where("#{table_name}.#{PaperTrail.timestamp_field} > ?", obj).
-          order(self.timestamp_sort_order)
+        where("#{table_name}.#{PaperTrail.timestamp_field} > ?", obj).order(self.timestamp_sort_order)
       end
 
       def preceding(obj, timestamp_arg = false)
@@ -51,8 +50,7 @@ module PaperTrail
         end
 
         obj = obj.send(PaperTrail.timestamp_field) if obj.is_a?(self)
-        where("#{table_name}.#{PaperTrail.timestamp_field} < ?", obj).
-          order(self.timestamp_sort_order('DESC'))
+        where("#{table_name}.#{PaperTrail.timestamp_field} < ?", obj).order(self.timestamp_sort_order('DESC'))
       end
 
 
@@ -63,9 +61,11 @@ module PaperTrail
 
       # defaults to using the primary key as the secondary sort order if possible
       def timestamp_sort_order(order = 'ASC')
-        self.primary_key_is_int? ?
-          "#{table_name}.#{PaperTrail.timestamp_field} #{order}, #{table_name}.#{self.primary_key} #{order}" :
+        if self.primary_key_is_int?
+          "#{table_name}.#{PaperTrail.timestamp_field} #{order}, #{table_name}.#{self.primary_key} #{order}"
+        else
           "#{table_name}.#{PaperTrail.timestamp_field} #{order}"
+        end
       end
 
       def primary_key_is_int?

test/unit/version_test.rb

@@ -65,7 +65,7 @@ class PaperTrail::VersionTest < ActiveSupport::TestCase
     setup { 2.times { @animal.update_attributes(:name => Faker::Lorem.word) } }
 
     context "receiving a TimeStamp" do
-      should "return all versions that were created before the Timestamp; descendingly by order of the `PaperTrail.timestamp_field`" do
+      should "return all versions that were created before the Timestamp" do
         value = PaperTrail::Version.subsequent(1.hour.ago, true)
         assert_equal value, @animal.versions.to_a
         assert_not_nil value.to_sql.match(/ORDER BY versions.created_at ASC/)
@@ -84,8 +84,8 @@ class PaperTrail::VersionTest < ActiveSupport::TestCase
     setup { 2.times { @animal.update_attributes(:name => Faker::Lorem.word) } }
 
     context "receiving a TimeStamp" do
-      should "return all versions that were created before the Timestamp; descendingly by order of the `PaperTrail.timestamp_field`" do
-        value = PaperTrail::Version.preceding(Time.now, true)
+      should "return all versions that were created before the Timestamp" do
+        value = PaperTrail::Version.preceding(5.seconds.from_now, true)
         assert_equal value, @animal.versions.reverse
         assert_not_nil value.to_sql.match(/ORDER BY versions.created_at DESC/)
       end