Fixed mutation error dependency registration.

src/HotChocolate/Core/src/Types.Mutations/Errors/MutationErrorHandler.cs

@@ -6,7 +6,20 @@ namespace HotChocolate.Types;
 public abstract class MutationErrorConfiguration
 {
     /// <summary>
-    /// Allows to register errors with a mutation.
+    /// Override to register error dependencies. 
+    /// </summary>
+    /// <param name="context">
+    /// The descriptor context.
+    /// </param>
+    /// <returns>
+    /// Returns the dependency references.
+    /// </returns>
+    public virtual IEnumerable<TypeReference> OnResolveDependencies(
+        IDescriptorContext context)
+        => Array.Empty<TypeReference>();
+
+    /// <summary>
+    /// Override to register errors with a mutation.
     /// </summary>
     /// <param name="context">
     /// The descriptor context.

src/HotChocolate/Core/src/Types.Mutations/Errors/MutationErrorTypeInterceptor.cs

@@ -1,9 +1,29 @@
+using System.Linq;
+
 namespace HotChocolate.Types;
 
 internal sealed class MutationErrorTypeInterceptor<T>(T errorRegistrar) 
     : TypeInterceptor
     where T : MutationErrorConfiguration
 {
+    internal override void OnBeforeCreateSchemaInternal(
+        IDescriptorContext context, 
+        ISchemaBuilder schemaBuilder)
+    {
+        var b = (SchemaBuilder)schemaBuilder;
+        foreach (var typeReference in errorRegistrar.OnResolveDependencies(context))
+        {
+            b.AddTypeReference(typeReference);
+        }
+    }
+
+    public override IEnumerable<TypeReference> RegisterMoreTypes(
+        IReadOnlyCollection<ITypeDiscoveryContext> discoveryContexts)
+    {
+        var context = discoveryContexts.First();
+        return errorRegistrar.OnResolveDependencies(context.DescriptorContext);
+    }
+
     public override void OnBeforeCompleteMutationField(
         ITypeCompletionContext completionContext, 
         ObjectFieldDefinition mutationField)

src/HotChocolate/Core/src/Types.Mutations/Extensions/ObjectFieldDefinitionExtensions.cs

@@ -62,5 +62,11 @@ public static void AddErrorType(
         }
 
         errorFactories.AddRange(definitions);
+
+        foreach (var definition in definitions)
+        {
+            var typeRef = descriptorContext.TypeInspector.GetTypeRef(definition.SchemaType);
+            fieldDefinition.Dependencies.Add(new TypeDependency(typeRef));
+        }
     }
 }

src/HotChocolate/Core/src/Types/SchemaBuilder.cs

@@ -261,6 +261,16 @@ public ISchemaBuilder AddType(INamedTypeExtension typeExtension)
         _types.Add(_ => TypeReference.Create(typeExtension));
         return this;
     }
+
+    internal void AddTypeReference(TypeReference typeReference)
+    {
+        if (typeReference is null)
+        {
+            throw new ArgumentNullException(nameof(typeReference));
+        }
+
+        _types.Add(_ => typeReference);
+    }
 
     /// <inheritdoc />
     public ISchemaBuilder AddDirectiveType(DirectiveType type)