public void TestGetAttachments() { //arrange var fileListingItemFullName1 = "d1"; var fileListingItemMock1 = new Mock <IFileListingModel>(); fileListingItemMock1.SetupGet(it => it.FullName).Returns(fileListingItemFullName1); var fileListingItemFullName2 = "d2"; var fileListingItemMock2 = new Mock <IFileListingModel>(); fileListingItemMock2.SetupGet(it => it.FullName).Returns(fileListingItemFullName2); _target.Drives = new List <FileListingModel>() { new FileListingModel( _modelMock.Object, fileListingItemMock1.Object, () => { }) { IsChecked = true }, new FileListingModel( _modelMock.Object, fileListingItemMock2.Object, () => { }) { IsChecked = true } }; _changedProperties.Clear(); //act var result = _target.GetAttachments(); //assert Assert.IsTrue(result.Contains(fileListingItemFullName1)); Assert.IsTrue(result.Contains(fileListingItemFullName2)); }