Fixed: also hide links for missing controllers on deeply nested relationships from includes

Author: Bart Koelman

src/JsonApiDotNetCore/Serialization/Response/LinkBuilder.cs

@@ -255,14 +255,6 @@ private bool ShouldIncludeResourceLink(LinkTypes linkType, ResourceType resource
     private string? GetLinkForResourceSelf(ResourceType resourceType, IIdentifiable resource)
     {
         string? controllerName = _controllerResourceMapping.GetControllerNameForResourceType(resourceType);
-
-        if (controllerName == null)
-        {
-            // When passing null to RenderLinkForAction, it uses the controller for the current endpoint. This is incorrect for
-            // included resources of a different resource type: it should hide their Self links when there's no controller for them.
-            return null;
-        }
-
         IDictionary<string, object?> routeValues = GetRouteValues(resource.StringId!, null);
 
         return RenderLinkForAction(controllerName, GetPrimaryControllerActionName, routeValues);
@@ -320,6 +312,13 @@ private bool ShouldIncludeResourceLink(LinkTypes linkType, ResourceType resource
 
     protected virtual string? RenderLinkForAction(string? controllerName, string actionName, IDictionary<string, object?> routeValues)
     {
+        if (controllerName == null)
+        {
+            // When passing null to LinkGenerator, it uses the controller for the current endpoint. This is incorrect for
+            // included resources of a different resource type: it should hide its links when there's no controller for them.
+            return null;
+        }
+
         return _options.UseRelativeLinks
             ? _linkGenerator.GetPathByAction(HttpContext, actionName, controllerName, routeValues)
             : _linkGenerator.GetUriByAction(HttpContext, actionName, controllerName, routeValues);

test/JsonApiDotNetCoreTests/IntegrationTests/Links/LinkInclusionIncludeTests.cs

@@ -19,7 +19,7 @@ public LinkInclusionIncludeTests(IntegrationTestContext<TestableStartup<LinksDbC
     }
 
     [Fact]
-    public async Task Hides_Self_link_in_included_resources_for_unregistered_controllers()
+    public async Task Hides_links_for_unregistered_controllers()
     {
         // Arrange
         PhotoLocation location = _fakers.PhotoLocation.Generate();
@@ -40,22 +40,26 @@ await _testContext.RunOnDatabaseAsync(async dbContext =>
         // Assert
         httpResponse.Should().HaveStatusCode(HttpStatusCode.OK);
 
+        responseDocument.Data.SingleValue.ShouldNotBeNull();
+
+        responseDocument.Data.SingleValue.Relationships.ShouldContainKey("photo").With(value =>
+        {
+            value.ShouldNotBeNull();
+            value.Links.ShouldNotBeNull();
+        });
+
         responseDocument.Included.ShouldHaveCount(2);
 
         responseDocument.Included.Should().ContainSingle(resource => resource.Type == "photos").Subject.With(resource =>
         {
             resource.Links.Should().BeNull();
-
-            resource.Relationships.ShouldContainKey("location").With(value =>
-            {
-                value.ShouldNotBeNull();
-                value.Links.ShouldNotBeNull();
-            });
+            resource.Relationships.Should().BeNull();
         });
 
         responseDocument.Included.Should().ContainSingle(resource => resource.Type == "photoAlbums").Subject.With(resource =>
         {
             resource.Links.Should().BeNull();
+            resource.Relationships.Should().BeNull();
         });
     }
 }

test/JsonApiDotNetCoreTests/IntegrationTests/ReadWrite/Creating/CreateResourceWithToOneRelationshipTests.cs

@@ -22,6 +22,7 @@ public CreateResourceWithToOneRelationshipTests(IntegrationTestContext<TestableS
         testContext.UseController<WorkItemGroupsController>();
         testContext.UseController<WorkItemsController>();
         testContext.UseController<RgbColorsController>();
+        testContext.UseController<UserAccountsController>();
 
         var options = (JsonApiOptions)testContext.Factory.Services.GetRequiredService<IJsonApiOptions>();
         options.AllowClientGeneratedIds = true;

test/JsonApiDotNetCoreTests/IntegrationTests/ReadWrite/Fetching/FetchResourceTests.cs

@@ -17,6 +17,7 @@ public FetchResourceTests(IntegrationTestContext<TestableStartup<ReadWriteDbCont
 
         testContext.UseController<WorkItemsController>();
         testContext.UseController<UserAccountsController>();
+        testContext.UseController<WorkTagsController>();
     }
 
     [Fact]

test/JsonApiDotNetCoreTests/IntegrationTests/ReadWrite/Updating/Resources/ReplaceToManyRelationshipTests.cs

@@ -19,6 +19,7 @@ public ReplaceToManyRelationshipTests(IntegrationTestContext<TestableStartup<Rea
         _testContext = testContext;
 
         testContext.UseController<WorkItemsController>();
+        testContext.UseController<UserAccountsController>();
 
         testContext.ConfigureServicesAfterStartup(services =>
         {

test/JsonApiDotNetCoreTests/IntegrationTests/ReadWrite/Updating/Resources/UpdateToOneRelationshipTests.cs

@@ -20,6 +20,7 @@ public UpdateToOneRelationshipTests(IntegrationTestContext<TestableStartup<ReadW
         testContext.UseController<WorkItemsController>();
         testContext.UseController<WorkItemGroupsController>();
         testContext.UseController<RgbColorsController>();
+        testContext.UseController<UserAccountsController>();
 
         testContext.ConfigureServicesAfterStartup(services =>
         {

test/JsonApiDotNetCoreTests/IntegrationTests/ReadWrite/WorkTag.cs

@@ -5,6 +5,7 @@
 namespace JsonApiDotNetCoreTests.IntegrationTests.ReadWrite;
 
 [UsedImplicitly(ImplicitUseTargetFlags.Members)]
+[Resource(ControllerNamespace = "JsonApiDotNetCoreTests.IntegrationTests.ReadWrite")]
 public sealed class WorkTag : Identifiable<int>
 {
     [Attr]

test/JsonApiDotNetCoreTests/UnitTests/Links/LinkInclusionTests.cs

@@ -69,7 +69,10 @@ public void Applies_cascading_settings_for_top_level_links(LinkTypes linksInReso
             PrimaryId = "1",
             IsCollection = true,
             Kind = EndpointKind.Relationship,
-            Relationship = new HasOneAttribute()
+            Relationship = new HasOneAttribute
+            {
+                LeftType = exampleResourceType
+            }
         };
 
         var paginationContext = new PaginationContext