public void FieldListChangedEventExecute() { var catalog = new TypeCatalog(); var container = new CompositionContainer(catalog, false); var expressionServiceBase = Mock.Create<IExpressionServiceBase>(Behavior.Loose); container.ComposeExportedValue(expressionServiceBase); Ioc.InjectContainer(container); // arrange var vm = new ProcessCommandsViewModel { Model = new ProcessEdit() }; var responsiblePersonField = new FieldInfo { Name = "Responsible Person", SystemName = "ResponsiblePerson_f" }; var collectionUtilities = Mock.Create<ICollectionUtilities>(); Mock.Arrange(() => collectionUtilities.SortPersonFieldDefsWithAll(Arg.IsAny<List<FieldEdit>>())).Returns(new ObservableCollection<FieldInfo> { responsiblePersonField }); vm.CollectionUtilities = collectionUtilities; // act vm.HandleEvent(new FieldListChangedEvent(FieldOperation.Added, null)); // assert Assert.AreEqual(responsiblePersonField, vm.PersonFieldList.First()); Ioc.InjectContainer(null); }