the private message stream is different to normal streams, improving the ui a bit and collapsing conversations

spec/models/user_action_spec.rb

@@ -206,4 +206,55 @@ describe UserAction do
       @user.user_actions.where(action_type: UserAction::BOOKMARK).first.should be_nil
     end
   end
+
+
+  describe 'private messages' do
+
+    let(:user) do
+      Fabricate(:user)
+    end
+
+    let(:target_user) do
+      Fabricate(:user)
+    end
+
+    let(:private_message) do
+      PostCreator.create( user,
+                          raw: 'this is a private message',
+                          title: 'this is the pm title',
+                          target_usernames: target_user.username,
+                          archetype: Archetype::private_message
+                        )
+    end
+
+    let!(:response) do
+      PostCreator.create(user, raw: 'oops I forgot to mention this', topic_id: private_message.topic_id)
+    end
+
+    let!(:private_message2) do
+      PostCreator.create( target_user,
+                          raw: 'this is a private message',
+                          title: 'this is the pm title',
+                          target_usernames: user.username,
+                          archetype: Archetype::private_message
+                        )
+    end
+
+    it 'should collapse the inbox correctly' do
+
+      stream = UserAction.private_message_stream(UserAction::GOT_PRIVATE_MESSAGE, user_id: target_user.id, guardian: Guardian.new(target_user))
+      # inbox should collapse this initial and reply message into one item
+      stream.count.should == 1
+
+
+      # outbox should also collapse
+      stream = UserAction.private_message_stream(UserAction::NEW_PRIVATE_MESSAGE, user_id: user.id, guardian: Guardian.new(user))
+      stream.count.should == 1
+
+      # anon should see nothing
+      stream = UserAction.private_message_stream(UserAction::NEW_PRIVATE_MESSAGE, user_id: user.id, guardian: Guardian.new(nil))
+      stream.count.should == 0
+
+    end
+  end
 end