Fix/compound relationship inclusion

src/JsonApiDotNetCore/Builders/DocumentBuilder.cs

@@ -169,25 +169,28 @@ private List<DocumentData> _getIncludedEntities(ContextEntity contextEntity, IId
 
                 if (navigationEntity is IEnumerable)
                     foreach (var includedEntity in (IEnumerable)navigationEntity)
-                        included.Add(_getIncludedEntity((IIdentifiable)includedEntity));
+                        _addIncludedEntity(included, (IIdentifiable)includedEntity);
                 else
-                    included.Add(_getIncludedEntity((IIdentifiable)navigationEntity));
+                    _addIncludedEntity(included, (IIdentifiable)navigationEntity);
             });
 
             return included;
         }
 
+        private void _addIncludedEntity(List<DocumentData> entities, IIdentifiable entity)
+        {
+            var includedEntity = _getIncludedEntity(entity);
+            if(includedEntity != null)
+                entities.Add(includedEntity);
+        }
+
         private DocumentData _getIncludedEntity(IIdentifiable entity)
         {
             if(entity == null) return null;
 
             var contextEntity = _jsonApiContext.ContextGraph.GetContextEntity(entity.GetType());
 
-            var data = new DocumentData
-            {
-                Type = contextEntity.EntityName,
-                Id = entity.StringId
-            };
+            var data = _getData(contextEntity, entity);
 
             data.Attributes = new Dictionary<string, object>();
 

test/JsonApiDotNetCoreExampleTests/Acceptance/Spec/FetchingDataTests.cs

@@ -2,8 +2,10 @@
 using System.Net;
 using System.Net.Http;
 using System.Threading.Tasks;
+using Bogus;
 using DotNetCoreDocs;
 using DotNetCoreDocs.Writers;
+using JsonApiDotNetCore.Models;
 using JsonApiDotNetCore.Serialization;
 using JsonApiDotNetCore.Services;
 using JsonApiDotNetCoreExample;
@@ -13,6 +15,7 @@
 using Microsoft.AspNetCore.TestHost;
 using Newtonsoft.Json;
 using Xunit;
+using Person = JsonApiDotNetCoreExample.Models.Person;
 
 namespace JsonApiDotNetCoreExampleTests.Acceptance.Spec
 {
@@ -21,11 +24,19 @@ public class FetchingDataTests
     {
         private DocsFixture<Startup, JsonDocWriter> _fixture;
         private IJsonApiContext _jsonApiContext;
+        private Faker<TodoItem> _todoItemFaker;
+        private Faker<Person> _personFaker;
 
         public FetchingDataTests(DocsFixture<Startup, JsonDocWriter> fixture)
         {
             _fixture = fixture;
             _jsonApiContext = fixture.GetService<IJsonApiContext>();
+            _todoItemFaker = new Faker<TodoItem>()
+                .RuleFor(t => t.Description, f => f.Lorem.Sentence())
+                .RuleFor(t => t.Ordinal, f => f.Random.Number());
+            _personFaker = new Faker<Person>()
+                .RuleFor(p => p.FirstName, f => f.Name.FirstName())
+                .RuleFor(p => p.LastName, f => f.Name.LastName());
         }
 
         [Fact]
@@ -60,5 +71,38 @@ public async Task Request_ForEmptyCollection_Returns_EmptyDataCollection()
 
             context.Dispose();
         }
+
+        [Fact]
+        public async Task Included_Records_Contain_Relationship_Links()
+        {
+            // arrange
+            var context = _fixture.GetService<AppDbContext>();
+            var todoItem = _todoItemFaker.Generate();
+            var person = _personFaker.Generate();
+            todoItem.Owner = person;
+            context.TodoItems.Add(todoItem);
+            await context.SaveChangesAsync();
+
+            var builder = new WebHostBuilder()
+                .UseStartup<Startup>();
+            var httpMethod = new HttpMethod("GET");
+            var route = $"/api/v1/todo-items/{todoItem.Id}?include=owner";
+            var server = new TestServer(builder);
+            var client = server.CreateClient();
+            var request = new HttpRequestMessage(httpMethod, route);
+
+            // act
+            var response = await client.SendAsync(request);
+            var body = await response.Content.ReadAsStringAsync();
+            var deserializedBody = JsonConvert.DeserializeObject<Document>(body);
+
+            // assert
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+            Assert.Equal(person.StringId, deserializedBody.Included[0].Id);
+            Assert.NotNull(deserializedBody.Included[0].Relationships);
+            Assert.Equal($"http://localhost/api/v1/people/{person.Id}/todo-items", deserializedBody.Included[0].Relationships["todo-items"].Links.Related);
+            Assert.Equal($"http://localhost/api/v1/people/{person.Id}/relationships/todo-items", deserializedBody.Included[0].Relationships["todo-items"].Links.Self);
+            context.Dispose();
+        }
     }
 }