Support query param operations on nested resources

src/Examples/JsonApiDotNetCoreExample/Models/TodoItem.cs

@@ -38,7 +38,9 @@ public TodoItem()
         public DateTimeOffset? OffsetDate { get; set; }
 
         public int? OwnerId { get; set; }
+
         public int? AssigneeId { get; set; }
+
         public Guid? CollectionId { get; set; }
 
         [HasOne]
@@ -49,6 +51,7 @@ public TodoItem()
 
         [HasOne]
         public virtual Person OneToOnePerson { get; set; }
+
         public virtual int? OneToOnePersonId { get; set; }
 
         [HasMany]
@@ -59,13 +62,16 @@ public TodoItem()
 
         // cyclical to-one structure
         public virtual int? DependentOnTodoId { get; set; }
+
         [HasOne]
         public virtual TodoItem DependentOnTodo { get; set; }
 
         // cyclical to-many structure
         public virtual int? ParentTodoId {get; set;}
+
         [HasOne]
         public virtual TodoItem ParentTodo { get; set; }
+
         [HasMany]
         public virtual List<TodoItem> ChildrenTodos { get; set; }
     }

src/JsonApiDotNetCore/Controllers/JsonApiController.cs

@@ -9,7 +9,6 @@ namespace JsonApiDotNetCore.Controllers
 {
     public class JsonApiController<T, TId> : BaseJsonApiController<T, TId> where T : class, IIdentifiable<TId>
     {
-
         /// <param name="jsonApiOptions"></param>
         /// <param name="resourceService"></param>
         /// <param name="loggerFactory"></param>

src/JsonApiDotNetCore/QueryParameterServices/Common/QueryParameterService.cs

@@ -1,11 +1,9 @@
-using System.Collections.Generic;
-using System.Linq;
+using System.Linq;
 using System.Text.RegularExpressions;
 using JsonApiDotNetCore.Internal;
 using JsonApiDotNetCore.Internal.Contracts;
 using JsonApiDotNetCore.Managers.Contracts;
 using JsonApiDotNetCore.Models;
-using Microsoft.Extensions.Primitives;
 
 namespace JsonApiDotNetCore.Query
 {
@@ -16,11 +14,20 @@ public abstract class QueryParameterService
     {
         protected readonly IResourceGraph _resourceGraph;
         protected readonly ResourceContext _requestResource;
+        private readonly ResourceContext _mainRequestResource;
 
         protected QueryParameterService(IResourceGraph resourceGraph, ICurrentRequest currentRequest)
         {
+            _mainRequestResource = currentRequest.GetRequestResource();
             _resourceGraph = resourceGraph;
-            _requestResource = currentRequest.GetRequestResource();
+            if (currentRequest.RequestRelationship != null)
+            {
+                _requestResource= resourceGraph.GetResourceContext(currentRequest.RequestRelationship.RightType);
+            }
+            else
+            {
+                _requestResource = _mainRequestResource;
+            }
         }
 
         protected QueryParameterService() { }
@@ -70,5 +77,16 @@ protected RelationshipAttribute GetRelationship(string propertyName)
 
             return relationship;
         }
+
+        /// <summary>
+        /// Throw an exception if query parameters are requested that are unsupported on nested resource routes.
+        /// </summary>
+        protected void EnsureNoNestedResourceRoute()
+        {
+            if (_requestResource != _mainRequestResource)
+            {
+                throw new JsonApiException(400, $"Query parameter {Name} is currently not supported on nested resource endpoints (i.e. of the form '/article/1/author?{Name}=...'");
+            }
+        }
     }
 }

src/JsonApiDotNetCore/QueryParameterServices/FilterService.cs

@@ -31,6 +31,7 @@ public List<FilterQueryContext> Get()
         /// <inheritdoc/>
         public virtual void Parse(KeyValuePair<string, StringValues> queryParameter)
         {
+            EnsureNoNestedResourceRoute();
             var queries = GetFilterQueries(queryParameter);
             _filters.AddRange(queries.Select(GetQueryContexts));
         }

src/JsonApiDotNetCore/QueryParameterServices/PageService.cs

@@ -2,7 +2,9 @@
 using System.Collections.Generic;
 using JsonApiDotNetCore.Configuration;
 using JsonApiDotNetCore.Internal;
+using JsonApiDotNetCore.Internal.Contracts;
 using JsonApiDotNetCore.Internal.Query;
+using JsonApiDotNetCore.Managers.Contracts;
 using Microsoft.Extensions.Primitives;
 
 namespace JsonApiDotNetCore.Query
@@ -12,7 +14,16 @@ public class PageService : QueryParameterService, IPageService
     {
         private readonly IJsonApiOptions _options;
 
-        public PageService(IJsonApiOptions options)
+        public PageService(IJsonApiOptions options, IResourceGraph resourceGraph, ICurrentRequest currentRequest) : base(resourceGraph, currentRequest)
+        {
+            _options = options;
+            PageSize = _options.DefaultPageSize;
+        }
+
+        /// <summary>
+        /// constructor used for unit testing
+        /// </summary>
+        internal PageService(IJsonApiOptions options)
         {
             _options = options;
             PageSize = _options.DefaultPageSize;
@@ -39,6 +50,7 @@ public PageService(IJsonApiOptions options)
         /// <inheritdoc/>
         public virtual void Parse(KeyValuePair<string, StringValues> queryParameter)
         {
+            EnsureNoNestedResourceRoute();
             // expected input = page[size]=<integer>
             //                  page[number]=<integer > 0>
             var propertyName = queryParameter.Key.Split(QueryConstants.OPEN_BRACKET, QueryConstants.CLOSE_BRACKET)[1];

src/JsonApiDotNetCore/QueryParameterServices/SortService.cs

@@ -28,6 +28,7 @@ public SortService(IResourceDefinitionProvider resourceDefinitionProvider,
         /// <inheritdoc/>
         public virtual void Parse(KeyValuePair<string, StringValues> queryParameter)
         {
+            EnsureNoNestedResourceRoute();
             CheckIfProcessed(); // disallow multiple sort parameters.
             var queries = BuildQueries(queryParameter.Value);
 

src/JsonApiDotNetCore/QueryParameterServices/SparseFieldsService.cs

@@ -45,6 +45,7 @@ public virtual void Parse(KeyValuePair<string, StringValues> queryParameter)
         {   // expected: articles?fields=prop1,prop2
             //           articles?fields[articles]=prop1,prop2  <-- this form in invalid UNLESS "articles" is actually a relationship on Article
             //           articles?fields[relationship]=prop1,prop2
+            EnsureNoNestedResourceRoute();
             var fields = new List<string> { nameof(Identifiable.Id) };
             fields.AddRange(((string)queryParameter.Value).Split(QueryConstants.COMMA));
 

src/JsonApiDotNetCore/Services/DefaultResourceService.cs

@@ -80,7 +80,7 @@ public virtual async Task<bool> DeleteAsync(TId id)
             if (!IsNull(_hookExecutor, entity)) _hookExecutor.AfterDelete(AsList(entity), ResourcePipeline.Delete, succeeded);
             return succeeded;
         }
-
+        
         public virtual async Task<IEnumerable<TResource>> GetAsync()
         {
             _hookExecutor?.BeforeRead<TResource>(ResourcePipeline.Get);
@@ -134,10 +134,15 @@ public virtual async Task<TResource> GetRelationshipsAsync(TId id, string relati
 
             // TODO: it would be better if we could distinguish whether or not the relationship was not found,
             // vs the relationship not being set on the instance of T
-            var entityQuery = _repository.Include(_repository.Get(id), new RelationshipAttribute[] { relationship });
+
+            var entityQuery = ApplyInclude(_repository.Get(id), chainPrefix: new List<RelationshipAttribute> { relationship });
             var entity = await _repository.FirstOrDefaultAsync(entityQuery);
-            if (entity == null) // this does not make sense. If the parent entity is not found, this error is thrown?
+            if (entity == null)
+            {
+                /// TODO: this does not make sense. If the **parent** entity is not found, this error is thrown?
+                /// this error should be thrown when the relationship is not found.
                 throw new JsonApiException(404, $"Relationship '{relationshipName}' not found.");
+            }
 
             if (!IsNull(_hookExecutor, entity))
             {   // AfterRead and OnReturn resource hook execution.
@@ -251,12 +256,34 @@ protected virtual IQueryable<TResource> ApplyFilter(IQueryable<TResource> entiti
         /// </summary>
         /// <param name="entities"></param>
         /// <returns></returns>
-        protected virtual IQueryable<TResource> ApplyInclude(IQueryable<TResource> entities)
+        protected virtual IQueryable<TResource> ApplyInclude(IQueryable<TResource> entities, IEnumerable<RelationshipAttribute> chainPrefix = null)
         {
             var chains = _includeService.Get();
-            if (chains != null && chains.Any())
-                foreach (var r in chains)
-                    entities = _repository.Include(entities, r.ToArray());
+            bool hasInclusionChain = chains.Any();
+
+            if (chains == null)
+            {
+                throw new Exception();
+            }
+
+            if (chainPrefix != null && !hasInclusionChain)
+            {
+               hasInclusionChain = true;
+               chains.Add(new List<RelationshipAttribute>());
+            }
+
+
+            if (hasInclusionChain)
+            {
+                foreach (var inclusionChain in chains)
+                {
+                    if (chainPrefix != null)
+                    {
+                        inclusionChain.InsertRange(0, chainPrefix);
+                    }
+                    entities = _repository.Include(entities, inclusionChain.ToArray());
+                }
+            }
 
             return entities;
         }

test/JsonApiDotNetCoreExampleTests/Acceptance/Spec/NestedResourceTests.cs

@@ -0,0 +1,72 @@
+using System.Linq;
+using System.Net;
+using System.Threading.Tasks;
+using Bogus;
+using JsonApiDotNetCoreExample.Models;
+using JsonApiDotNetCoreExampleTests.Helpers.Models;
+using Xunit;
+using Person = JsonApiDotNetCoreExample.Models.Person;
+
+namespace JsonApiDotNetCoreExampleTests.Acceptance.Spec
+{
+    public class NestedResourceTests : FunctionalTestCollection<StandardApplicationFactory>
+    {
+        private readonly Faker<TodoItem> _todoItemFaker;
+        private readonly Faker<Person> _personFaker;
+        private readonly Faker<Passport> _passportFaker;
+
+        public NestedResourceTests(StandardApplicationFactory factory) : base(factory)
+        {
+            _todoItemFaker = new Faker<TodoItem>()
+                    .RuleFor(t => t.Description, f => f.Lorem.Sentence())
+                    .RuleFor(t => t.Ordinal, f => f.Random.Number())
+                    .RuleFor(t => t.CreatedDate, f => f.Date.Past());
+            _personFaker = new Faker<Person>()
+                    .RuleFor(t => t.FirstName, f => f.Name.FirstName())
+                    .RuleFor(t => t.LastName, f => f.Name.LastName());
+            _passportFaker = new Faker<Passport>()
+                    .RuleFor(t => t.SocialSecurityNumber, f => f.Random.Number());
+        }
+
+        [Fact]
+        public async Task NestedResourceRoute_RequestWithIncludeQueryParam_ReturnsRequestedRelationships()
+        {
+            // Arrange
+            var assignee = _dbContext.Add(_personFaker.Generate()).Entity;
+            var todo = _dbContext.Add(_todoItemFaker.Generate()).Entity;
+            var owner = _dbContext.Add(_personFaker.Generate()).Entity;
+            var passport = _dbContext.Add(_passportFaker.Generate()).Entity;
+            _dbContext.SaveChanges();
+            todo.AssigneeId = assignee.Id;
+            todo.OwnerId = owner.Id;
+            owner.PassportId = passport.Id;
+            _dbContext.SaveChanges();
+
+            // Act
+            var (body, response) = await Get($"/api/v1/people/{assignee.Id}/assignedTodoItems?include=owner.passport");
+
+            // Assert
+            AssertEqualStatusCode(HttpStatusCode.OK, response);
+            var resultTodoItem = _deserializer.DeserializeList<TodoItemClient>(body).Data.SingleOrDefault();
+            Assert.Equal(todo.Id, resultTodoItem.Id);
+            Assert.Equal(todo.Owner.Id, resultTodoItem.Owner.Id);
+            Assert.Equal(todo.Owner.Passport.Id, resultTodoItem.Owner.Passport.Id);
+        }
+
+        [Theory]
+        [InlineData("filter[ordinal]=1")]
+        [InlineData("fields=ordinal")]
+        [InlineData("sort=ordinal")]
+        [InlineData("page[number]=1")]
+        [InlineData("page[size]=10")]
+        public async Task NestedResourceRoute_RequestWithUnsupportedQueryParam_ReturnsBadRequest(string queryParam)
+        {
+            // Act
+            var (body, response) = await Get($"/api/v1/people/1/assignedTodoItems?{queryParam}");
+
+            // Assert
+            AssertEqualStatusCode(HttpStatusCode.BadRequest, response);
+            Assert.Contains("currently not supported", body);
+        }
+    }
+}

test/UnitTests/Services/EntityResourceService_Tests.cs

@@ -19,9 +19,21 @@ public class EntityResourceService_Tests
     {
         private readonly Mock<IResourceRepository<TodoItem>> _repositoryMock = new Mock<IResourceRepository<TodoItem>>();
         private readonly IResourceGraph _resourceGraph;
+        private readonly Mock<IIncludeService> _includeService;
+        private readonly Mock<ISparseFieldsService> _sparseFieldsService;
+        private readonly Mock<IPageService> _pageService;
+
+        public Mock<ISortService> _sortService { get; }
+        public Mock<IFilterService> _filterService { get; }
 
         public EntityResourceService_Tests()
         {
+            _includeService = new Mock<IIncludeService>();
+            _includeService.Setup(m => m.Get()).Returns(new List<List<RelationshipAttribute>>());
+            _sparseFieldsService = new Mock<ISparseFieldsService>();
+            _pageService = new Mock<IPageService>();
+            _sortService = new Mock<ISortService>();
+            _filterService = new Mock<IFilterService>();
             _resourceGraph = new ResourceGraphBuilder()
                                 .AddResource<TodoItem>()
                                 .AddResource<TodoItemCollection, Guid>()
@@ -87,7 +99,13 @@ public async Task GetRelationshipAsync_Returns_Relationship_Value()
 
         private DefaultResourceService<TodoItem> GetService()
         {
-            return new DefaultResourceService<TodoItem>(new List<IQueryParameterService>(), new JsonApiOptions(), _repositoryMock.Object, _resourceGraph);
+            var queryParamServices = new List<IQueryParameterService>
+            {
+                _includeService.Object, _pageService.Object, _filterService.Object,
+                _sortService.Object, _sparseFieldsService.Object
+            };
+
+            return new DefaultResourceService<TodoItem>(queryParamServices, new JsonApiOptions(), _repositoryMock.Object, _resourceGraph);
         }
     }
 }