Replaced ActionResults with rich exceptions

Fixes in handling of missing relationships + extra tests

Author: Bart Koelman

src/Examples/JsonApiDotNetCoreExample/Controllers/TodoItemsCustomController.cs

@@ -3,11 +3,11 @@
 using System.Threading.Tasks;
 using JsonApiDotNetCore.Configuration;
 using JsonApiDotNetCore.Controllers;
+using JsonApiDotNetCore.Exceptions;
 using JsonApiDotNetCore.Models;
 using JsonApiDotNetCore.Services;
 using JsonApiDotNetCoreExample.Models;
 using Microsoft.AspNetCore.Mvc;
-using Microsoft.Extensions.Logging;
 
 namespace JsonApiDotNetCoreExample.Controllers
 {
@@ -17,9 +17,8 @@ public class TodoItemsCustomController : CustomJsonApiController<TodoItem>
     {
         public TodoItemsCustomController(
             IJsonApiOptions options,
-            IResourceService<TodoItem> resourceService,
-            ILoggerFactory loggerFactory) 
-            : base(options, resourceService, loggerFactory)
+            IResourceService<TodoItem> resourceService) 
+            : base(options, resourceService)
         { }
     }
 
@@ -28,8 +27,7 @@ public class CustomJsonApiController<T>
     {
         public CustomJsonApiController(
             IJsonApiOptions options,
-            IResourceService<T, int> resourceService,
-            ILoggerFactory loggerFactory)
+            IResourceService<T, int> resourceService)
             : base(options, resourceService)
         {
         }
@@ -70,22 +68,29 @@ public async Task<IActionResult> GetAsync()
         [HttpGet("{id}")]
         public async Task<IActionResult> GetAsync(TId id)
         {
-            var entity = await _resourceService.GetAsync(id);
-
-            if (entity == null)
+            try
+            {
+                var entity = await _resourceService.GetAsync(id);
+                return Ok(entity);
+            }
+            catch (ResourceNotFoundException)
+            {
                 return NotFound();
-
-            return Ok(entity);
+            }
         }
 
         [HttpGet("{id}/relationships/{relationshipName}")]
         public async Task<IActionResult> GetRelationshipsAsync(TId id, string relationshipName)
         {
-            var relationship = _resourceService.GetRelationshipAsync(id, relationshipName);
-            if (relationship == null)
+            try
+            {
+                var relationship = await _resourceService.GetRelationshipsAsync(id, relationshipName);
+                return Ok(relationship);
+            }
+            catch (ResourceNotFoundException)
+            {
                 return NotFound();
-
-            return await GetRelationshipAsync(id, relationshipName);
+            }
         }
 
         [HttpGet("{id}/{relationshipName}")]
@@ -115,12 +120,15 @@ public async Task<IActionResult> PatchAsync(TId id, [FromBody] T entity)
             if (entity == null)
                 return UnprocessableEntity();
 
-            var updatedEntity = await _resourceService.UpdateAsync(id, entity);
-
-            if (updatedEntity == null)
+            try
+            {
+                var updatedEntity = await _resourceService.UpdateAsync(id, entity);
+                return Ok(updatedEntity);
+            }
+            catch (ResourceNotFoundException)
+            {
                 return NotFound();
-
-            return Ok(updatedEntity);
+            }
         }
 
         [HttpPatch("{id}/relationships/{relationshipName}")]
@@ -133,11 +141,7 @@ public async Task<IActionResult> PatchRelationshipsAsync(TId id, string relation
         [HttpDelete("{id}")]
         public async Task<IActionResult> DeleteAsync(TId id)
         {
-            var wasDeleted = await _resourceService.DeleteAsync(id);
-
-            if (!wasDeleted)
-                return NotFound();
-
+            await _resourceService.DeleteAsync(id);
             return NoContent();
         }
     }

src/Examples/NoEntityFrameworkExample/Services/TodoItemService.cs

@@ -63,7 +63,7 @@ public async Task<TodoItem> CreateAsync(TodoItem entity)
             })).SingleOrDefault();
         }
 
-        public Task<bool> DeleteAsync(int id)
+        public Task DeleteAsync(int id)
         {
             throw new NotImplementedException();
         }

src/JsonApiDotNetCore/Controllers/BaseJsonApiController.cs

@@ -78,11 +78,6 @@ public virtual async Task<IActionResult> GetAsync(TId id)
 
             if (_getById == null) throw new RequestMethodNotAllowedException(HttpMethod.Get);
             var entity = await _getById.GetAsync(id);
-            if (entity == null)
-            {
-                return NotFound();
-            }
-
             return Ok(entity);
         }
 
@@ -92,10 +87,6 @@ public virtual async Task<IActionResult> GetRelationshipsAsync(TId id, string re
 
             if (_getRelationships == null) throw new RequestMethodNotAllowedException(HttpMethod.Get);
             var relationship = await _getRelationships.GetRelationshipsAsync(id, relationshipName);
-            if (relationship == null)
-            {
-                return NotFound();
-            }
 
             return Ok(relationship);
         }
@@ -117,17 +108,17 @@ public virtual async Task<IActionResult> PostAsync([FromBody] T entity)
                 throw new RequestMethodNotAllowedException(HttpMethod.Post);
 
             if (entity == null)
-                return UnprocessableEntity();
+                throw new InvalidRequestBodyException(null, null, null);
 
             if (!_jsonApiOptions.AllowClientGeneratedIds && !string.IsNullOrEmpty(entity.StringId))
-                return Forbidden();
+                throw new ResourceIdInPostRequestNotAllowedException();
 
             if (_jsonApiOptions.ValidateModelState && !ModelState.IsValid)
                 throw new InvalidModelStateException(ModelState, typeof(T), _jsonApiOptions);
 
             entity = await _create.CreateAsync(entity);
 
-            return Created($"{HttpContext.Request.Path}/{entity.Id}", entity);
+            return Created($"{HttpContext.Request.Path}/{entity.StringId}", entity);
         }
 
         public virtual async Task<IActionResult> PatchAsync(TId id, [FromBody] T entity)
@@ -136,19 +127,12 @@ public virtual async Task<IActionResult> PatchAsync(TId id, [FromBody] T entity)
 
             if (_update == null) throw new RequestMethodNotAllowedException(HttpMethod.Patch);
             if (entity == null)
-                return UnprocessableEntity();
+                throw new InvalidRequestBodyException(null, null, null);
 
             if (_jsonApiOptions.ValidateModelState && !ModelState.IsValid)
                 throw new InvalidModelStateException(ModelState, typeof(T), _jsonApiOptions);
 
             var updatedEntity = await _update.UpdateAsync(id, entity);
-
-            if (updatedEntity == null)
-            {
-                return NotFound();
-            }
-
-
             return Ok(updatedEntity);
         }
 
@@ -166,9 +150,8 @@ public virtual async Task<IActionResult> DeleteAsync(TId id)
             _logger.LogTrace($"Entering {nameof(DeleteAsync)}('{id}).");
 
             if (_delete == null) throw new RequestMethodNotAllowedException(HttpMethod.Delete);
-            var wasDeleted = await _delete.DeleteAsync(id);
-            if (!wasDeleted)
-                return NotFound();
+            await _delete.DeleteAsync(id);
+
             return NoContent();
         }
     }

src/JsonApiDotNetCore/Controllers/JsonApiControllerMixin.cs

@@ -1,6 +1,5 @@
 using System.Collections.Generic;
 using System.Linq;
-using System.Net;
 using JsonApiDotNetCore.Middleware;
 using JsonApiDotNetCore.Models.JsonApiDocuments;
 using Microsoft.AspNetCore.Mvc;
@@ -10,17 +9,12 @@ namespace JsonApiDotNetCore.Controllers
     [ServiceFilter(typeof(IQueryParameterActionFilter))]
     public abstract class JsonApiControllerMixin : ControllerBase
     {
-        protected IActionResult Forbidden()
-        {
-            return new StatusCodeResult((int)HttpStatusCode.Forbidden);
-        }
-
         protected IActionResult Error(Error error)
         {
-            return Errors(new[] {error});
+            return Error(new[] {error});
         }
 
-        protected IActionResult Errors(IEnumerable<Error> errors)
+        protected IActionResult Error(IEnumerable<Error> errors)
         {
             var document = new ErrorDocument(errors.ToList());
 

src/JsonApiDotNetCore/Exceptions/JsonApiException.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Net;
 using JsonApiDotNetCore.Models.JsonApiDocuments;
 using Newtonsoft.Json;
 
@@ -26,15 +25,6 @@ public JsonApiException(Error error, Exception innerException)
             Error = error;
         }
 
-        public JsonApiException(HttpStatusCode status, string message)
-            : base(message)
-        {
-            Error = new Error(status)
-            {
-                Title = message
-            };
-        }
-
         public override string Message => "Error = " + JsonConvert.SerializeObject(Error, _errorSerializerSettings);
     }
 }

src/JsonApiDotNetCore/Exceptions/RelationshipNotFoundException.cs

@@ -0,0 +1,19 @@
+using System.Net;
+using JsonApiDotNetCore.Models.JsonApiDocuments;
+
+namespace JsonApiDotNetCore.Exceptions
+{
+    /// <summary>
+    /// The error that is thrown when a relationship does not exist.
+    /// </summary>
+    public sealed class RelationshipNotFoundException : JsonApiException
+    {
+        public RelationshipNotFoundException(string relationshipName, string containingResourceName) : base(new Error(HttpStatusCode.NotFound)
+        {
+            Title = "The requested relationship does not exist.",
+            Detail = $"The resource '{containingResourceName}' does not contain a relationship named '{relationshipName}'."
+        })
+        {
+        }
+    }
+}

src/JsonApiDotNetCore/Exceptions/ResourceIdInPostRequestNotAllowedException.cs

@@ -0,0 +1,23 @@
+using System.Net;
+using JsonApiDotNetCore.Models.JsonApiDocuments;
+
+namespace JsonApiDotNetCore.Exceptions
+{
+    /// <summary>
+    /// The error that is thrown when a POST request is received that contains a client-generated ID.
+    /// </summary>
+    public sealed class ResourceIdInPostRequestNotAllowedException : JsonApiException
+    {
+        public ResourceIdInPostRequestNotAllowedException()
+            : base(new Error(HttpStatusCode.Forbidden)
+            {
+                Title = "Specifying the resource id in POST requests is not allowed.",
+                Source =
+                {
+                    Pointer = "/data/id"
+                }
+            })
+        {
+        }
+    }
+}

src/JsonApiDotNetCore/Exceptions/ResourceNotFoundException.cs

@@ -0,0 +1,19 @@
+using System.Net;
+using JsonApiDotNetCore.Models.JsonApiDocuments;
+
+namespace JsonApiDotNetCore.Exceptions
+{
+    /// <summary>
+    /// The error that is thrown when a resource does not exist.
+    /// </summary>
+    public sealed class ResourceNotFoundException : JsonApiException
+    {
+        public ResourceNotFoundException(string resourceId, string resourceType) : base(new Error(HttpStatusCode.NotFound)
+        {
+            Title = "The requested resource does not exist.",
+            Detail = $"Resource of type '{resourceType}' with id '{resourceId}' does not exist."
+        })
+        {
+        }
+    }
+}

src/JsonApiDotNetCore/Extensions/TypeExtensions.cs

@@ -5,6 +5,7 @@
 using System.Linq;
 using System.Net;
 using JsonApiDotNetCore.Exceptions;
+using JsonApiDotNetCore.Models;
 
 namespace JsonApiDotNetCore.Extensions
 {
@@ -83,6 +84,13 @@ public static IEnumerable GetEmptyCollection(this Type t)
             return list;
         }
 
+        public static string GetResourceStringId<TResource, TId>(TId id) where TResource : class, IIdentifiable<TId>
+        {
+            var tempResource = typeof(TResource).New<TResource>();
+            tempResource.Id = id;
+            return tempResource.StringId;
+        }
+
         public static object New(this Type t)
         {
             return New<object>(t);

src/JsonApiDotNetCore/Middleware/CurrentRequestMiddleware.cs

@@ -233,7 +233,7 @@ private ResourceContext GetCurrentEntity()
             }
             if (_routeValues.TryGetValue("relationshipName", out object relationshipName))
             {
-                _currentRequest.RequestRelationship = requestResource.Relationships.Single(r => r.PublicRelationshipName == (string)relationshipName);
+                _currentRequest.RequestRelationship = requestResource.Relationships.SingleOrDefault(r => r.PublicRelationshipName == (string)relationshipName);
             }
             return requestResource;
         }