Handle unmap_notify X events in Manager

lib/uh/wm/manager.rb

@@ -107,6 +107,10 @@ module Uh
         map event.window
       end
 
+      def handle_unmap_notify event
+        unmap event.window
+      end
+
       def client_for window
         @clients.find { |e| e.window == window }
       end

spec/uh/wm/manager_spec.rb

@@ -302,6 +302,15 @@ module Uh
             manager.handle event
           end
         end
+
+        context 'when unmap_notify event is given' do
+          let(:event) { double 'event', type: :unmap_notify, window: :window }
+
+          it 'unmap the event window' do
+            expect(manager).to receive(:unmap).with :window
+            manager.handle event
+          end
+        end
       end
     end
   end