feat: get relationship behaves different in OnReturn

Author: maurei

src/JsonApiDotNetCore/Hooks/ResourceHookExecutor.cs

@@ -200,7 +200,7 @@ public virtual IEnumerable<TEntity> OnReturn<TEntity>(IEnumerable<TEntity> entit
         {
             var hookContainer = _meta.GetResourceHookContainer<TEntity>(ResourceHook.OnReturn);
             var layer = _layerFactory.CreateLayer(entities);
-            if (hookContainer != null)
+            if (hookContainer != null && pipeline != ResourceAction.GetRelationship)
             {
                 var uniqueEntities = layer.GetAllUniqueEntities().Cast<TEntity>();
                 var filteredUniqueEntities = hookContainer.OnReturn(uniqueEntities, pipeline);

src/JsonApiDotNetCore/Services/EntityResourceService.cs

@@ -164,18 +164,17 @@ public virtual async Task<TResource> GetAsync(TId id)
 
         }
 
-        // triggered by route /articles/1/relationships/{relationshipName}
+        // triggered by GET /articles/1/relationships/{relationshipName}
         public virtual async Task<object> GetRelationshipsAsync(TId id, string relationshipName) => await GetRelationshipAsync(id, relationshipName);
 
-        // triggered by route /articles/1/{relationshipName}
+        // triggered by GET /articles/1/{relationshipName}
         public virtual async Task<object> GetRelationshipAsync(TId id, string relationshipName)
         {
 
             _hookExecutor?.BeforeRead<TEntity>(ResourceAction.GetRelationship, id.ToString());
             var entity = await _entities.GetAndIncludeAsync(id, relationshipName);
             if (!IsNull(_hookExecutor, entity))
             {
-                // TODO: should not fire after read for L=0
                 _hookExecutor.AfterRead(AsList(entity), ResourceAction.GetRelationship);
                 entity = _hookExecutor.OnReturn(AsList(entity), ResourceAction.GetRelationship).SingleOrDefault();
             }
@@ -216,6 +215,7 @@ public virtual async Task<TResource> UpdateAsync(TId id, TResource resource)
             return MapOut(entity);
         }
 
+        // triggered by PATCH /articles/1/relationships/{relationshipName}
         public virtual async Task UpdateRelationshipsAsync(TId id, string relationshipName, List<ResourceObject> relationships)
         {
             var entity = await _entities.GetAndIncludeAsync(id, relationshipName);
@@ -248,7 +248,7 @@ public virtual async Task UpdateRelationshipsAsync(TId id, string relationshipNa
 
             entity = IsNull(_hookExecutor) ? entity : _hookExecutor.BeforeUpdate(AsList(entity), ResourceAction.PatchRelationship).SingleOrDefault();
             await _entities.UpdateRelationshipsAsync(entity, relationship, relationshipIds);
-            if (!IsNull(_hookExecutor, entity)) _hookExecutor.AfterUpdate(AsList(entity), ResourceAction.Patch);
+            if (!IsNull(_hookExecutor, entity)) _hookExecutor.AfterUpdate(AsList(entity), ResourceAction.PatchRelationship);
 
             relationship.Type = relationshipType;
         }

test/UnitTests/ResourceHooks/ResourceHookExecutor/IdentifiableManyToMany_OnReturnTests.cs

@@ -32,6 +32,26 @@ public void OnReturn()
             VerifyNoOtherCalls(articleResourceMock, joinResourceMock, tagResourceMock);
         }
 
+        [Fact]
+        public void OnReturn_GetRelationship()
+        {
+            // arrange
+            var articleDiscovery = SetDiscoverableHooks<Article>(targetHooks, DisableDbValues);
+            var joinDiscovery = SetDiscoverableHooks<IdentifiableArticleTag>(targetHooks, DisableDbValues);
+            var tagDiscovery = SetDiscoverableHooks<Tag>(targetHooks, DisableDbValues);
+            (var contextMock, var hookExecutor, var articleResourceMock,
+                var joinResourceMock, var tagResourceMock) = CreateTestObjects(articleDiscovery, joinDiscovery, tagDiscovery);
+            (var articles, var joins, var tags) = CreateIdentifiableManyToManyData();
+
+            // act
+            hookExecutor.OnReturn(articles, ResourceAction.GetRelationship);
+
+            // assert
+            joinResourceMock.Verify(rd => rd.OnReturn(It.Is<IEnumerable<IdentifiableArticleTag>>((collection) => !collection.Except(joins).Any()), ResourceAction.GetRelationship), Times.Once());
+            tagResourceMock.Verify(rd => rd.OnReturn(It.Is<IEnumerable<Tag>>((collection) => !collection.Except(tags).Any()), ResourceAction.GetRelationship), Times.Once());
+            VerifyNoOtherCalls(articleResourceMock, joinResourceMock, tagResourceMock);
+        }
+
         [Fact]
         public void OnReturn_Without_Parent_Hook_Implemented()
         {