Fix for OnReturn hook in GetSecondary pipeline (#926)

* fix invalid casting issue for get secondary resource on return hook
* unit test and simplified usage of dynamic

Author: maurei

src/JsonApiDotNetCore/Hooks/Internal/ResourceHookExecutor.cs

@@ -118,7 +118,7 @@ public IEnumerable<TResource> BeforeDelete<TResource>(IEnumerable<TResource> res
         /// <inheritdoc />
         public IEnumerable<TResource> OnReturn<TResource>(IEnumerable<TResource> resources, ResourcePipeline pipeline) where TResource : class, IIdentifiable
         {
-            if (GetHook(ResourceHook.OnReturn, resources, out var container, out var node) && pipeline != ResourcePipeline.GetRelationship)
+            if (GetHook(ResourceHook.OnReturn, resources, out var container, out var node))
             {
                 IEnumerable<TResource> updated = container.OnReturn((HashSet<TResource>)node.UniqueResources, pipeline);
                 ValidateHookResponse(updated);

src/JsonApiDotNetCore/Hooks/Internal/ResourceHookExecutorFacade.cs

@@ -119,9 +119,9 @@ public IReadOnlyCollection<TResource> OnReturnMany<TResource>(IReadOnlyCollectio
 
         public object OnReturnRelationship(object resourceOrResources)
         {
-            if (resourceOrResources is IEnumerable enumerable)
+            if (resourceOrResources is IEnumerable)
             {
-                var resources = enumerable.Cast<IIdentifiable>();
+                dynamic resources = resourceOrResources;
                 return _resourceHookExecutor.OnReturn(resources, ResourcePipeline.GetRelationship).ToArray();
             }
 

test/JsonApiDotNetCoreExampleTests/Acceptance/ResourceDefinitions/ResourceDefinitionTests.cs

@@ -217,6 +217,30 @@ public async Task Article_Is_Hidden()
             Assert.DoesNotContain(toBeExcluded, body);
         }
 
+        [Fact]
+        public async Task Article_Through_Secondary_Endpoint_Is_Hidden()
+        {
+            // Arrange
+            var articles = _articleFaker.Generate(3);
+            string toBeExcluded = "This should not be included";
+            articles[0].Caption = toBeExcluded;
+            var author = _authorFaker.Generate();
+            author.Articles = articles;
+
+            _dbContext.AuthorDifferentDbContextName.Add(author);
+            await _dbContext.SaveChangesAsync();
+
+            var route = $"/api/v1/authors/{author.Id}/articles";
+
+            // Act
+            var response = await _client.GetAsync(route);
+
+            // Assert
+            var body = await response.Content.ReadAsStringAsync();
+            Assert.True(HttpStatusCode.OK == response.StatusCode, $"{route} returned {response.StatusCode} status code with body: {body}");
+            Assert.DoesNotContain(toBeExcluded, body);
+        }
+
         [Fact]
         public async Task Tag_Is_Hidden()
         {

test/UnitTests/ResourceHooks/ResourceHookExecutor/IdentifiableManyToMany_OnReturnTests.cs

@@ -45,6 +45,7 @@ public void OnReturn_GetRelationship()
             hookExecutor.OnReturn(articles, ResourcePipeline.GetRelationship);
 
             // Assert
+            articleResourceMock.Verify(rd => rd.OnReturn(It.Is<HashSet<Article>>((collection) => !collection.Except(articles).Any()), ResourcePipeline.GetRelationship), Times.Once());
             joinResourceMock.Verify(rd => rd.OnReturn(It.Is<HashSet<IdentifiableArticleTag>>((collection) => !collection.Except(joins).Any()), ResourcePipeline.GetRelationship), Times.Once());
             tagResourceMock.Verify(rd => rd.OnReturn(It.Is<HashSet<Tag>>((collection) => !collection.Except(tags).Any()), ResourcePipeline.GetRelationship), Times.Once());
             VerifyNoOtherCalls(articleResourceMock, joinResourceMock, tagResourceMock);