feat: TaskCreation_Fails_MessageNotifiesUserAndTasksIsNotAddedToTheList

Author: Xiphereal

Desktop.Tests/UnitTests/TaskCreationViewModelTests.cs

@@ -0,0 +1,32 @@
+using Desktop.Common;
+using Desktop.Tasks;
+using Desktop.Tests.TestAPI;
+using FluentAssertions;
+using Moq;
+using NUnit.Framework;
+using static Desktop.Tests.TestAPI.TaskFactory;
+
+namespace Desktop.Tests.UnitTests;
+
+public class TaskCreationViewModelTests
+{
+    [Test]
+    public void TaskCreation_Fails_MessageNotifiesUserAndTasksIsNotAddedToTheList()
+    {
+        var repository = new InMemoryTaskRepository([AnyDesktopTask()]);
+        repository.FailAlways();
+        var messageNotifierMock = new Mock<IMessageNotifier>();
+        var sut = new TaskCreationViewModel(
+            messageNotifierMock.Object,
+            [repository]);
+        var closeable = new Mock<ICloseable>();
+
+        sut.SaveTask.Execute((closeable.Object, "Any name", "Any description"));
+
+        messageNotifierMock.Verify(x => x.Notify(
+            "Task creation has failed due to " +
+            "an internal error. The Task won't be created. " +
+            "Please, try again later."));
+        sut.CreatedTask.Should().BeNull();
+    }
+}

Desktop.Tests/UnitTests/TaskListViewModelTests.cs

@@ -69,13 +69,13 @@ public void TaskDeletion_Fails_MessageNotifiesUserAndTaskRemains()
         var existingTask = DesktopTask();
         var backendRepository =
             new InMemoryTaskRepository([existingTask]);
-        
+
         var messageNotifierMock = new Mock<IMessageNotifier>();
-        
+
         var sut = TaskListViewModel(backendRepository, messageNotifierMock.Object);
         sut.PopulateTasks();
         backendRepository.FailAlways();
-        
+
         // Act.
         sut.Delete.Execute(existingTask);
 
@@ -90,10 +90,11 @@ public void TaskDeletion_Fails_MessageNotifiesUserAndTaskRemains()
     private static TaskListViewModel TaskListViewModel(
         params InMemoryTaskRepository[] taskRepositories)
     {
+        var messageNotifier = new Mock<IMessageNotifier>().Object;
         return new TaskListViewModel(
             taskRepositories,
-            new TaskCreationViewModel(taskRepositories),
-            new Mock<IMessageNotifier>().Object);
+            new TaskCreationViewModel(messageNotifier, taskRepositories),
+            messageNotifier);
     }
 
     private static TaskListViewModel TaskListViewModel(
@@ -102,7 +103,7 @@ private static TaskListViewModel TaskListViewModel(
     {
         return new TaskListViewModel(
             [taskRepository],
-            new TaskCreationViewModel([taskRepository]),
+            new TaskCreationViewModel(messageNotifier, [taskRepository]),
             messageNotifier);
     }
 }

Desktop/Tasks/TaskCreationViewModel.cs

@@ -6,7 +6,9 @@ namespace Desktop.Tasks;
 
 public class TaskCreationViewModel : ViewModelBase
 {
-    public TaskCreationViewModel(IEnumerable<ITaskRepository> taskRepositories)
+    public TaskCreationViewModel(
+        IMessageNotifier messageNotifier,
+        IEnumerable<ITaskRepository> taskRepositories)
     {
         SaveTask =
             new AsyncRelayCommand<(ICloseable, string, string)>(async args =>
@@ -17,7 +19,19 @@ public TaskCreationViewModel(IEnumerable<ITaskRepository> taskRepositories)
 
                 foreach (var repository in taskRepositories)
                 {
-                    await repository.Save(CreatedTask);
+                    var creationResult = await repository.Save(CreatedTask);
+
+                    if (!creationResult.Succeeded)
+                    {
+                        messageNotifier.Notify(
+                            "Task creation has failed due to " +
+                            "an internal error. The Task won't be created. " +
+                            "Please, try again later.");
+
+                        CreatedTask = null;
+
+                        break;
+                    }
                 }
 
                 closeable!.Close();