wip: new 422 validation errors with source.pointer

Author: rtablada

src/JsonApiDotNetCore/Controllers/BaseJsonApiController.cs

@@ -8,7 +8,7 @@
 
 namespace JsonApiDotNetCore.Controllers
 {
-    public class BaseJsonApiController<T> 
+    public class BaseJsonApiController<T>
         : BaseJsonApiController<T, int>
         where T : class, IIdentifiable<int>
     {
@@ -47,7 +47,7 @@ public class BaseJsonApiController<T, TId>
         private readonly ICreateService<T, TId> _create;
         private readonly IUpdateService<T, TId> _update;
         private readonly IUpdateRelationshipService<T, TId> _updateRelationships;
-        private readonly IDeleteService<T, TId> _delete;        
+        private readonly IDeleteService<T, TId> _delete;
         private readonly IJsonApiContext _jsonApiContext;
 
         public BaseJsonApiController(
@@ -156,7 +156,7 @@ public virtual async Task<IActionResult> PostAsync([FromBody] T entity)
                 return Forbidden();
 
             if (_jsonApiContext.Options.ValidateModelState && !ModelState.IsValid)
-                return BadRequest(ModelState.ConvertToErrorCollection());
+                return BadRequest(ModelState.ConvertToErrorCollection(_jsonApiContext.ContextGraph));
 
             entity = await _create.CreateAsync(entity);
 
@@ -170,7 +170,7 @@ public virtual async Task<IActionResult> PatchAsync(TId id, [FromBody] T entity)
             if (entity == null)
                 return UnprocessableEntity();
             if (_jsonApiContext.Options.ValidateModelState && !ModelState.IsValid)
-                return BadRequest(ModelState.ConvertToErrorCollection());
+                return BadRequest(ModelState.ConvertToErrorCollection(_jsonApiContext.ContextGraph));
 
             var updatedEntity = await _update.UpdateAsync(id, entity);
 

src/JsonApiDotNetCore/Extensions/ModelStateExtensions.cs

@@ -6,7 +6,7 @@ namespace JsonApiDotNetCore.Extensions
 {
     public static class ModelStateExtensions
     {
-        public static ErrorCollection ConvertToErrorCollection(this ModelStateDictionary modelState)
+        public static ErrorCollection ConvertToErrorCollection(this ModelStateDictionary modelState, IContextGraph contextGraph)
         {
             ErrorCollection collection = new ErrorCollection();
             foreach (var entry in modelState)
@@ -16,10 +16,19 @@ public static ErrorCollection ConvertToErrorCollection(this ModelStateDictionary
 
                 foreach (var modelError in entry.Value.Errors)
                 {
+                    var attrName = entry.Key;
+
                     if (modelError.Exception is JsonApiException jex)
                         collection.Errors.AddRange(jex.GetError().Errors);
                     else
-                        collection.Errors.Add(new Error(400, entry.Key, modelError.ErrorMessage, modelError.Exception != null ? ErrorMeta.FromException(modelError.Exception) : null));
+                        collection.Errors.Add(new Error(
+                            status: 422,
+                            title: entry.Key,
+                            detail: modelError.ErrorMessage,
+                            meta: modelError.Exception != null ? ErrorMeta.FromException(modelError.Exception) : null,
+                            source: new {
+                                pointer = $"/data/attributes/{attrName}"
+                            }));
                 }
             }