public void Should_Throw_When_CommandIsNull()
        {
            var settingsStore = Substitute.For <ISettingsStore>();

            var handler = new MoveDownCommandHandler(settingsStore);

            handler.Handle(null);
        }
        public void Should_MoveDown_And_Save()
        {
            var settingsStore = Substitute.For <ISettingsStore>();
            var item          = Substitute.For <Item>();
            var command       = new MoveDownCommand(item);
            var handler       = new MoveDownCommandHandler(settingsStore);

            handler.Handle(command);

            item.Received().MoveDown();
            settingsStore.Received().TrySave();
        }