Fixed :next_version method to return the live model when appropriate. C…

…lose #200

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## 2.7.1 (Unreleased)
 
+  - [#200](https://github.com/airblade/paper_trail/issues/200) - Fixed `next_version` method so that it returns the live model
+    when called on latest reified version of a model prior to the live model.
   - [#197](https://github.com/airblade/paper_trail/issues/197) - PaperTrail now falls back on using YAML for serialization of
     serialized model attributes for storage in the `object` and `object_changes` columns in the `Version` table. This fixes
     compatibility for `Rails 3.0.x` for projects that employ the `serialize` declaration on a model.

lib/paper_trail/has_paper_trail.rb

@@ -155,15 +155,17 @@ def versions_between(start_time, end_time, reify_options={})
       # Returns the object (not a Version) as it was most recently.
       def previous_version
         preceding_version = source_version ? source_version.previous : send(self.class.versions_association_name).last
-        preceding_version.try :reify
+        preceding_version.reify if preceding_version
       end
 
       # Returns the object (not a Version) as it became next.
+      # NOTE: if self (the item) was not reified from a version, i.e. it is the
+      #  "live" item, we return nil.  Perhaps we should return self instead?
       def next_version
-        # NOTE: if self (the item) was not reified from a version, i.e. it is the
-        # "live" item, we return nil.  Perhaps we should return self instead?
-        subsequent_version = source_version ? source_version.next : nil
-        subsequent_version.reify if subsequent_version
+        subsequent_version = source_version.next
+        subsequent_version ? subsequent_version.reify : self.class.find(self.id)
+      rescue
+        nil
       end
 
       # Executes the given method or block without creating a new version.

test/unit/model_test.rb

@@ -795,32 +795,31 @@ def without(&block)
       end
 
       should 'have a previous version' do
-        assert_equal @widget.versions.last.reify, @widget.previous_version
+        assert_equal @widget.versions.last.reify.name, @widget.previous_version.name
       end
 
-      should 'have a next version' do
+      should 'not have a next version' do
         assert_nil @widget.next_version
       end
     end
   end
 
   context 'A reified item' do
     setup do
-      widget = Widget.create :name => 'Bob'
-      %w( Tom Dick Jane ).each { |name| widget.update_attributes :name => name }
-      @versions      = widget.versions
-      @second_widget = @versions[1].reify  # first widget is null
-      @last_widget   = @versions.last.reify
+      @widget = Widget.create :name => 'Bob'
+      %w(Tom Dick Jane).each { |name| @widget.update_attributes :name => name }
+      @second_widget = @widget.versions[1].reify  # first widget is `nil`
+      @last_widget   = @widget.versions.last.reify
     end
 
     should 'have a previous version' do
-      assert_nil @second_widget.previous_version
-      assert_equal @versions[-2].reify, @last_widget.previous_version
+      assert_nil @second_widget.previous_version # `create` events return `nil` for `reify`
+      assert_equal @widget.versions[-2].reify.name, @last_widget.previous_version.name
     end
 
     should 'have a next version' do
-      assert_equal @versions[2].reify, @second_widget.next_version
-      assert_nil @last_widget.next_version
+      assert_equal @widget.versions[2].reify.name, @second_widget.next_version.name
+      assert_equal @last_widget.next_version.name, @widget.name
     end
   end
 
@@ -1106,7 +1105,11 @@ def without(&block)
       assert_equal 2, @doc.paper_trail_versions.length
     end
 
-    should 'respond to previous_version as normal' do
+    should 'respond to `next_version` as normal' do
+      assert_equal @doc.paper_trail_versions.last.reify.next_version.name, @doc.name
+    end
+
+    should 'respond to `previous_version` as normal' do
       @doc.update_attributes :name => 'Doc 2'
       assert_equal 3, @doc.paper_trail_versions.length
       assert_equal 'Doc 1', @doc.previous_version.name