public void ToolBarCommandsDelegation() { var lazyShellViewModel = new Lazy <IShellViewModel>(() => new MockShellViewModel()); var shellService = new ShellService(lazyShellViewModel); var mockShellViewModel = (MockShellViewModel)lazyShellViewModel.Value; var emptyCommand = new DelegateCommand(() => { }); var newToolBarCommands = new ToolBarCommand[] { new ToolBarCommand(emptyCommand, "Command 1"), new ToolBarCommand(emptyCommand, "Command 2") }; Assert.IsFalse(mockShellViewModel.ToolBarCommands.Any()); shellService.AddToolBarCommands(newToolBarCommands); Assert.IsTrue(mockShellViewModel.ToolBarCommands.SequenceEqual(newToolBarCommands)); shellService.ClearToolBarCommands(); Assert.IsFalse(mockShellViewModel.ToolBarCommands.Any()); }