Merge pull request #189 from brocktimus/master

Only propagating updated_at if records have been changed with touch option

lib/ancestry/has_ancestry.rb

@@ -74,9 +74,9 @@ def has_ancestry options = {}
       }
     end
 
-    after_save :touch_ancestors_callback
     after_touch :touch_ancestors_callback
     after_destroy :touch_ancestors_callback
+    after_save :touch_ancestors_callback, if: :changed?
   end
 end
 
@@ -86,4 +86,4 @@ class << ActiveRecord::Base
       alias_method :acts_as_tree, :has_ancestry
     end
   end
-end
+end

test/concerns/touching_test.rb

@@ -16,7 +16,7 @@ def test_touch_option_disabled
     end
   end
 
-  def test_touch_option_enabled
+  def test_touch_option_enabled_propagates_with_modification
     AncestryTestDatabase.with_model(
       :extra_columns => {:updated_at => :datetime},
       :touch => true
@@ -44,4 +44,25 @@ def test_touch_option_enabled
       assert_equal way_back, child_1_2.reload.updated_at,        "unrelated record was touched"
     end
   end
-end
+
+  def test_touch_option_enabled_doesnt_propagate_without_modification
+    AncestryTestDatabase.with_model(
+      :extra_columns => {:updated_at => :datetime},
+      :touch => true
+    ) do |model|
+
+      way_back = Time.new(1984)
+      recently = Time.now - 1.minute
+
+      parent      = model.create!
+      child       = model.create!(:parent => parent)
+      grandchild  = model.create!(:parent => child)
+      model.update_all(updated_at: way_back)
+      grandchild.save
+
+      assert_equal way_back, grandchild.reload.updated_at, "main record updated_at timestamp was touched"
+      assert_equal way_back, child.reload.updated_at,      "parent record was touched"
+      assert_equal way_back, parent.reload.updated_at,     "grandparent record was touched"
+    end
+  end
+end