feat(webapi): Return 410 GONE for notification checks on deleted dialogs (#1387)

<!--- Provide a general summary of your changes in the Title above -->

## Description

<!--- Describe your changes in detail -->

## Related Issue(s)

- #1386 

## Verification

- [ ] **Your** code builds clean without any errors or warnings
- [ ] Manual testing done (required)
- [ ] Relevant automated test added (if you find this hard, leave it and
we'll help out)

## Documentation

- [ ] Documentation is updated (either in `docs`-directory, Altinnpedia
or a separate linked PR in
[altinn-studio-docs.](https://github.com/Altinn/altinn-studio-docs), if
applicable)


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
- Enhanced error handling for deleted entities in the notification
condition query.
- Added a new response type for deleted dialogs, improving clarity in
error reporting.

- **Bug Fixes**
- Improved response handling for scenarios where a requested dialog has
been deleted.

- **Tests**
- Introduced a new test case to verify correct behavior when querying a
deleted dialog.
	- Refactored test methods for improved readability and maintainability.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: oskogstad

src/Digdir.Domain.Dialogporten.Application/Features/V1/ServiceOwner/DialogActivities/Queries/NotificationCondition/NotificationConditionQuery.cs

@@ -23,7 +23,7 @@ public enum NotificationConditionType
 }
 
 [GenerateOneOf]
-public sealed partial class NotificationConditionResult : OneOfBase<NotificationConditionDto, ValidationError, EntityNotFound>;
+public sealed partial class NotificationConditionResult : OneOfBase<NotificationConditionDto, ValidationError, EntityNotFound, EntityDeleted>;
 
 internal sealed class NotificationConditionQueryHandler : IRequestHandler<NotificationConditionQuery, NotificationConditionResult>
 {
@@ -41,6 +41,7 @@ public async Task<NotificationConditionResult> Handle(NotificationConditionQuery
             .Include(x => x.Activities
                 .Where(x => request.TransmissionId == null || x.TransmissionId == request.TransmissionId)
                 .Where(x => x.TypeId == request.ActivityType))
+            .IgnoreQueryFilters()
             .FirstOrDefaultAsync(x => x.Id == request.DialogId,
                 cancellationToken: cancellationToken);
 
@@ -49,6 +50,11 @@ public async Task<NotificationConditionResult> Handle(NotificationConditionQuery
             return new EntityNotFound<DialogEntity>(request.DialogId);
         }
 
+        if (dialog.Deleted)
+        {
+            return new EntityDeleted<DialogEntity>(request.DialogId);
+        }
+
         var conditionMet = dialog.Activities.Count == 0
             ? request.ConditionType == NotificationConditionType.NotExists
             : request.ConditionType == NotificationConditionType.Exists;

src/Digdir.Domain.Dialogporten.WebApi/Endpoints/V1/ServiceOwner/DialogActivities/NotificationCondition/NotificationConditionEndpoint.cs

@@ -28,6 +28,7 @@ public override async Task HandleAsync(NotificationConditionQuery req, Cancellat
         await result.Match(
             dto => SendOkAsync(dto, ct),
             validationError => this.BadRequestAsync(validationError, ct),
-            notFound => this.NotFoundAsync(notFound, ct));
+            notFound => this.NotFoundAsync(notFound, ct),
+            deleted => this.GoneAsync(deleted, ct));
     }
 }

tests/Digdir.Domain.Dialogporten.Application.Integration.Tests/Features/V1/ServiceOwner/NotificationCondition/NotificationConditionTests.cs

@@ -1,5 +1,6 @@
 using Digdir.Domain.Dialogporten.Application.Features.V1.ServiceOwner.DialogActivities.Queries.NotificationCondition;
 using Digdir.Domain.Dialogporten.Application.Features.V1.ServiceOwner.Dialogs.Commands.Create;
+using Digdir.Domain.Dialogporten.Application.Features.V1.ServiceOwner.Dialogs.Commands.Delete;
 using Digdir.Domain.Dialogporten.Application.Integration.Tests.Common;
 using Digdir.Domain.Dialogporten.Domain.Dialogs.Entities.Activities;
 using Digdir.Domain.Dialogporten.Domain.Dialogs.Entities.Transmissions;
@@ -39,12 +40,7 @@ public async Task SendNotification_Should_Be_True_When_Conditions_Are_Met(
         var response = await Application.Send(createDialogCommand);
         response.TryPickT0(out var dialogId, out _);
 
-        var notificationConditionQuery = new NotificationConditionQuery
-        {
-            DialogId = dialogId.Value,
-            ActivityType = activityType,
-            ConditionType = conditionType,
-        };
+        var notificationConditionQuery = CreateNotificationConditionQuery(dialogId.Value, activityType, conditionType);
 
         if (activityType is DialogActivityType.Values.TransmissionOpened)
         {
@@ -79,12 +75,7 @@ private static void AddActivityRequirements(
     public async Task NotFound_Should_Be_Returned_When_Dialog_Does_Not_Exist()
     {
         // Arrange
-        var notificationConditionQuery = new NotificationConditionQuery
-        {
-            DialogId = Guid.NewGuid(),
-            ActivityType = DialogActivityType.Values.Information,
-            ConditionType = NotificationConditionType.Exists,
-        };
+        var notificationConditionQuery = CreateNotificationConditionQuery(Guid.NewGuid());
 
         // Act
         var queryResult = await Application.Send(notificationConditionQuery);
@@ -94,4 +85,37 @@ public async Task NotFound_Should_Be_Returned_When_Dialog_Does_Not_Exist()
         queryResult.IsT2.Should().BeTrue();
         notFound.Should().NotBeNull();
     }
+
+    [Fact]
+    public async Task Gone_Should_Be_Returned_When_Dialog_Is_Deleted()
+    {
+        // Arrange
+        var createDialogCommand = DialogGenerator.GenerateSimpleFakeDialog();
+
+        var response = await Application.Send(createDialogCommand);
+        response.TryPickT0(out var dialogId, out _);
+
+        await Application.Send(new DeleteDialogCommand { Id = dialogId.Value });
+
+        var notificationConditionQuery = CreateNotificationConditionQuery(dialogId.Value);
+
+        // Act
+        var queryResult = await Application.Send(notificationConditionQuery);
+
+        // Assert
+        queryResult.TryPickT3(out var deleted, out _);
+        queryResult.IsT3.Should().BeTrue();
+        deleted.Should().NotBeNull();
+        deleted.Message.Should().Contain(dialogId.Value.ToString());
+    }
+
+    private static NotificationConditionQuery CreateNotificationConditionQuery(Guid dialogId,
+        DialogActivityType.Values activityType = DialogActivityType.Values.Information,
+        NotificationConditionType conditionType = NotificationConditionType.Exists)
+        => new()
+        {
+            DialogId = dialogId,
+            ActivityType = activityType,
+            ConditionType = conditionType,
+        };
 }