Allow use of deletion callback for rollback events.

Related to #1021.

lib/thinking_sphinx/active_record/callbacks/delete_callbacks.rb

@@ -1,18 +1,26 @@
 class ThinkingSphinx::ActiveRecord::Callbacks::DeleteCallbacks <
   ThinkingSphinx::Callbacks
 
-  callbacks :after_destroy
+  callbacks :after_destroy, :after_rollback
 
   def after_destroy
+    delete_from_sphinx
+  end
+
+  def after_rollback
+    delete_from_sphinx
+  end
+
+  private
+
+  def delete_from_sphinx
     return if ThinkingSphinx::Callbacks.suspended? || instance.new_record?
 
     indices.each { |index|
       ThinkingSphinx::Deletion.perform index, instance.id
     }
   end
 
-  private
-
   def indices
     ThinkingSphinx::Configuration.instance.index_set_class.new(
       :classes => [instance.class]

spec/thinking_sphinx/active_record/callbacks/delete_callbacks_spec.rb

@@ -64,4 +64,63 @@
       ThinkingSphinx::Callbacks.resume!
     end
   end
+
+  describe '.after_rollback' do
+    let(:callbacks) { double('callbacks', :after_rollback => nil) }
+
+    before :each do
+      allow(ThinkingSphinx::ActiveRecord::Callbacks::DeleteCallbacks).
+        to receive_messages :new => callbacks
+    end
+
+    it "builds an object from the instance" do
+      expect(ThinkingSphinx::ActiveRecord::Callbacks::DeleteCallbacks).
+        to receive(:new).with(instance).and_return(callbacks)
+
+      ThinkingSphinx::ActiveRecord::Callbacks::DeleteCallbacks.
+        after_rollback(instance)
+    end
+
+    it "invokes after_rollback on the object" do
+      expect(callbacks).to receive(:after_rollback)
+
+      ThinkingSphinx::ActiveRecord::Callbacks::DeleteCallbacks.
+        after_rollback(instance)
+    end
+  end
+
+  describe '#after_rollback' do
+    let(:index_set)  { double 'index set', :to_a => [index] }
+    let(:index)      { double('index', :name => 'foo_core',
+      :document_id_for_key => 14, :type => 'plain', :distributed? => false) }
+    let(:instance)   { double('instance', :id => 7, :new_record? => false) }
+
+    before :each do
+      allow(ThinkingSphinx::IndexSet).to receive_messages :new => index_set
+    end
+
+    it "performs the deletion for the index and instance" do
+      expect(ThinkingSphinx::Deletion).to receive(:perform).with(index, 7)
+
+      callbacks.after_rollback
+    end
+
+    it "doesn't do anything if the instance is a new record" do
+      allow(instance).to receive_messages :new_record? => true
+
+      expect(ThinkingSphinx::Deletion).not_to receive(:perform)
+
+      callbacks.after_rollback
+    end
+
+    it 'does nothing if callbacks are suspended' do
+      ThinkingSphinx::Callbacks.suspend!
+
+      expect(ThinkingSphinx::Deletion).not_to receive(:perform)
+
+      callbacks.after_rollback
+
+      ThinkingSphinx::Callbacks.resume!
+    end
+  end
 end