Fixed: Override IIdentifiable.Id with custom capabilities no longer worked

Author: Bart Koelman

src/JsonApiDotNetCore/Configuration/ResourceGraphBuilder.cs

@@ -171,27 +171,22 @@ private IReadOnlyCollection<AttrAttribute> GetAttributes(Type resourceClrType)
 
         foreach (PropertyInfo property in resourceClrType.GetProperties())
         {
-            // Although strictly not correct, 'id' is added to the list of attributes for convenience.
-            // For example, it enables to filter on ID, without the need to special-case existing logic.
-            // And when using sparse fields, it silently adds 'id' to the set of attributes to retrieve.
-            if (property.Name == nameof(Identifiable<object>.Id))
-            {
-                var idAttr = new AttrAttribute
-                {
-                    PublicName = FormatPropertyName(property),
-                    Property = property,
-                    Capabilities = _options.DefaultAttrCapabilities
-                };
-
-                IncludeField(attributesByName, idAttr);
-                continue;
-            }
-
             var attribute = property.GetCustomAttribute<AttrAttribute>(true);
 
             if (attribute == null)
             {
-                continue;
+                if (property.Name == nameof(Identifiable<object>.Id))
+                {
+                    // Although strictly not correct, 'id' is added to the list of attributes for convenience.
+                    // For example, it enables to filter on ID, without the need to special-case existing logic.
+                    // And when using sparse fieldsets, it silently adds 'id' to the set of attributes to retrieve.
+
+                    attribute = new AttrAttribute();
+                }
+                else
+                {
+                    continue;
+                }
             }
 
             SetPublicName(attribute, property);

test/JsonApiDotNetCoreTests/UnitTests/ResourceGraph/ResourceGraphBuilderTests.cs

@@ -289,6 +289,28 @@ public void Resolves_correct_type_for_lazy_loading_proxy()
         resourceType.ClrType.Should().Be(typeof(ResourceOfInt32));
     }
 
+    [Fact]
+    public void Can_override_capabilities_on_Id_property()
+    {
+        // Arrange
+        var options = new JsonApiOptions
+        {
+            DefaultAttrCapabilities = AttrCapabilities.None
+        };
+
+        var builder = new ResourceGraphBuilder(options, NullLoggerFactory.Instance);
+
+        // Act
+        builder.Add<ResourceWithIdOverride, long>();
+
+        // Assert
+        IResourceGraph resourceGraph = builder.Build();
+        ResourceType resourceType = resourceGraph.GetResourceType<ResourceWithIdOverride>();
+
+        AttrAttribute idAttribute = resourceType.Attributes.Single(attr => attr.Property.Name == nameof(Identifiable<object>.Id));
+        idAttribute.Capabilities.Should().Be(AttrCapabilities.AllowFilter);
+    }
+
     [UsedImplicitly(ImplicitUseTargetFlags.Members)]
     private sealed class ResourceWithHasOneRelationship : Identifiable<int>
     {
@@ -376,4 +398,11 @@ public class ResourceOfInt32 : Identifiable<int>
         [HasMany]
         public IList<ResourceOfInt32> Children { get; set; } = new List<ResourceOfInt32>();
     }
+
+    [UsedImplicitly(ImplicitUseTargetFlags.Members)]
+    public sealed class ResourceWithIdOverride : Identifiable<long>
+    {
+        [Attr(Capabilities = AttrCapabilities.AllowFilter)]
+        public override long Id { get; set; }
+    }
 }