Allow to override the enum type name and value comparer

src/HotChocolate/Core/src/Abstractions/NameString.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Collections;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Globalization;
 using HotChocolate.Language;
@@ -234,3 +236,33 @@ internal static NameString ConvertFromString(string s)
             ? new NameString()
             : new NameString(s);
 }
+
+/// <summary>
+/// Provides comparers for <see cref="NameString"/>.
+/// </summary>
+public static class NameStringComparer
+{
+    public static IEqualityComparer<NameString> Ordinal { get; } =
+        new OrdinalComparer();
+
+    public static IEqualityComparer<NameString> OrdinalIgnoreCase { get; } =
+        new OrdinalIgnoreCaseComparer();
+
+    private sealed class OrdinalIgnoreCaseComparer : IEqualityComparer<NameString>
+    {
+        public bool Equals(NameString x, NameString y)
+            => x.Equals(y, StringComparison.OrdinalIgnoreCase);
+
+        public int GetHashCode(NameString obj)
+            => StringComparer.OrdinalIgnoreCase.GetHashCode(obj.Value);
+    }
+
+    private sealed class OrdinalComparer : IEqualityComparer<NameString>
+    {
+        public bool Equals(NameString x, NameString y)
+            => x.Equals(y, StringComparison.Ordinal);
+
+        public int GetHashCode(NameString obj)
+            => obj.Value.GetHashCode();
+    }
+}

src/HotChocolate/Core/src/Types/Types/Descriptors/Contracts/IEnumTypeDescriptor.cs

@@ -1,9 +1,13 @@
 using System;
+using System.Collections.Generic;
 using HotChocolate.Language;
 using HotChocolate.Types.Descriptors.Definitions;
 
 namespace HotChocolate.Types;
 
+/// <summary>
+/// A fluent configuration API for GraphQL enum types.
+/// </summary>
 public interface IEnumTypeDescriptor
     : IDescriptor<EnumTypeDefinition>
     , IFluent
@@ -34,6 +38,12 @@ IEnumTypeDescriptor SyntaxNode(
     /// </param>
     IEnumTypeDescriptor Description(string value);
 
+    /// <summary>
+    /// Defines a value that should be included on the enum type.
+    /// </summary>
+    /// <param name="value">
+    /// The value to include.
+    /// </param>
     [Obsolete("Use `Value`.")]
     IEnumValueDescriptor Item<T>(T value);
 
@@ -45,9 +55,21 @@ IEnumTypeDescriptor SyntaxNode(
     /// </param>
     IEnumValueDescriptor Value<T>(T value);
 
+    /// <summary>
+    /// Specifies if the enum values shall be inferred or explicitly specfied.
+    /// </summary>
+    /// <param name="behavior">
+    /// The binding behavior.
+    /// </param>
     [Obsolete("Use `BindValues`.")]
     IEnumTypeDescriptor BindItems(BindingBehavior behavior);
 
+    /// <summary>
+    /// Specifies if the enum values shall be inferred or explicitly specfied.
+    /// </summary>
+    /// <param name="behavior">
+    /// The binding behavior.
+    /// </param>
     IEnumTypeDescriptor BindValues(BindingBehavior behavior);
 
     /// <summary>
@@ -61,13 +83,55 @@ IEnumTypeDescriptor SyntaxNode(
     /// </summary>
     IEnumTypeDescriptor BindValuesImplicitly();
 
+    /// <summary>
+    /// Specifies the enum name comparer that will be used to validate
+    /// if an enum name represents an enum value of this type.
+    /// </summary>
+    /// <param name="comparer">
+    /// The equality comparer for enum names.
+    /// </param>
+    IEnumTypeDescriptor NameComparer(IEqualityComparer<NameString> comparer);
+
+    /// <summary>
+    /// Specifies the runtime value comparer that will be used to validate
+    /// if a runtime value represents a GraphQL enum value of this type.
+    /// </summary>
+    /// <param name="comparer">
+    /// The equality comparer for enum names.
+    /// </param>
+    IEnumTypeDescriptor ValueComparer(IEqualityComparer<object> comparer);
+
+    /// <summary>
+    /// Annotates a directive to this type.
+    /// </summary>
+    /// <param name="directiveInstance">
+    /// The directive that shall be annotated to this type.
+    /// </param>
+    /// <typeparam name="T">
+    /// The type of the directive instance.
+    /// </typeparam>
     IEnumTypeDescriptor Directive<T>(
         T directiveInstance)
         where T : class;
 
+    /// <summary>
+    /// Annotates a directive to this type.
+    /// </summary>
+    /// <typeparam name="T">
+    /// The type of the directive instance.
+    /// </typeparam>
     IEnumTypeDescriptor Directive<T>()
         where T : class, new();
 
+    /// <summary>
+    /// Annotates a directive to this type.
+    /// </summary>
+    /// <param name="name">
+    /// The name of the directive.
+    /// </param>
+    /// <param name="arguments">
+    /// The argument values that the directive instance shall have.
+    /// </param>
     IEnumTypeDescriptor Directive(
         NameString name,
         params ArgumentNode[] arguments);

src/HotChocolate/Core/src/Types/Types/Descriptors/Contracts/IEnumTypeDescriptor~1.cs

@@ -1,9 +1,16 @@
 using System;
+using System.Collections.Generic;
 using HotChocolate.Language;
 using HotChocolate.Types.Descriptors.Definitions;
 
 namespace HotChocolate.Types;
 
+/// <summary>
+/// A fluent configuration API for GraphQL enum types.
+/// </summary>
+/// <typeparam name="T">
+/// The runtime type.
+/// </typeparam>"
 public interface IEnumTypeDescriptor<T>
     : IDescriptor<EnumTypeDefinition>
     , IFluent
@@ -34,6 +41,12 @@ IEnumTypeDescriptor<T> SyntaxNode(
     /// </param>
     IEnumTypeDescriptor<T> Description(string value);
 
+    /// <summary>
+    /// Defines a value that should be included on the enum type.
+    /// </summary>
+    /// <param name="value">
+    /// The value to include.
+    /// </param>
     [Obsolete("Use `Value`.")]
     IEnumValueDescriptor Item(T value);
 
@@ -45,9 +58,21 @@ IEnumTypeDescriptor<T> SyntaxNode(
     /// </param>
     IEnumValueDescriptor Value(T value);
 
+    /// <summary>
+    /// Specifies if the enum values shall be inferred or explicitly specfied.
+    /// </summary>
+    /// <param name="behavior">
+    /// The binding behavior.
+    /// </param>
     [Obsolete("Use `BindValues`.")]
     IEnumTypeDescriptor<T> BindItems(BindingBehavior behavior);
 
+    /// <summary>
+    /// Specifies if the enum values shall be inferred or explicitly specfied.
+    /// </summary>
+    /// <param name="behavior">
+    /// The binding behavior.
+    /// </param>
     IEnumTypeDescriptor<T> BindValues(BindingBehavior behavior);
 
     /// <summary>
@@ -61,13 +86,55 @@ IEnumTypeDescriptor<T> SyntaxNode(
     /// </summary>
     IEnumTypeDescriptor<T> BindValuesImplicitly();
 
+    /// <summary>
+    /// Specifies the enum name comparer that will be used to validate
+    /// if an enum name represents an enum value of this type.
+    /// </summary>
+    /// <param name="comparer">
+    /// The equality comparer for enum names.
+    /// </param>
+    IEnumTypeDescriptor NameComparer(IEqualityComparer<NameString> comparer);
+
+    /// <summary>
+    /// Specifies the runtime value comparer that will be used to validate
+    /// if a runtime value represents a GraphQL enum value of this type.
+    /// </summary>
+    /// <param name="comparer">
+    /// The equality comparer for enum names.
+    /// </param>
+    IEnumTypeDescriptor ValueComparer(IEqualityComparer<object> comparer);
+
+    /// <summary>
+    /// Annotates a directive to this type.
+    /// </summary>
+    /// <param name="directiveInstance">
+    /// The directive that shall be annotated to this type.
+    /// </param>
+    /// <typeparam name="TDirective">
+    /// The type of the directive instance.
+    /// </typeparam>
     IEnumTypeDescriptor<T> Directive<TDirective>(
         TDirective directiveInstance)
         where TDirective : class;
 
+    /// <summary>
+    /// Annotates a directive to this type.
+    /// </summary>
+    /// <typeparam name="TDirective">
+    /// The type of the directive instance.
+    /// </typeparam>
     IEnumTypeDescriptor<T> Directive<TDirective>()
         where TDirective : class, new();
 
+    /// <summary>
+    /// Annotates a directive to this type.
+    /// </summary>
+    /// <param name="name">
+    /// The name of the directive.
+    /// </param>
+    /// <param name="arguments">
+    /// The argument values that the directive instance shall have.
+    /// </param>
     IEnumTypeDescriptor<T> Directive(
         NameString name,
         params ArgumentNode[] arguments);

src/HotChocolate/Core/src/Types/Types/Descriptors/Definitions/EnumTypeDefinition.cs

@@ -30,6 +30,20 @@ public EnumTypeDefinition(
         Description = description;
     }
 
+    /// <summary>
+    /// Gets or sets the enum name comparer that will be used to validate
+    /// if an enum name represents an enum value of this type.
+    /// </summary>
+    public IEqualityComparer<NameString> NameComparer { get; set; } =
+        NameStringComparer.Ordinal;
+
+    /// <summary>
+    /// Gets or sets the runtime value comparer that will be used to validate
+    /// if a runtime value represents a GraphQL enum value of this type.
+    /// </summary>
+    public IEqualityComparer<object> ValueComparer { get; set; } =
+        DefaultValueComparer.Instance;
+
     /// <summary>
     /// Gets the enum values.
     /// </summary>
@@ -57,4 +71,15 @@ public override IEnumerable<ITypeSystemMemberConfiguration> GetConfigurations()
 
         return configs ?? Enumerable.Empty<ITypeSystemMemberConfiguration>();
     }
+
+    private sealed class DefaultValueComparer : IEqualityComparer<object>
+    {
+        bool IEqualityComparer<object>.Equals(object? x, object? y)
+            => Equals(x, y);
+
+        int IEqualityComparer<object>.GetHashCode(object obj)
+            => obj.GetHashCode();
+
+        public static DefaultValueComparer Instance { get; } = new();
+    }
 }

src/HotChocolate/Core/src/Types/Types/Descriptors/EnumTypeDescriptor.cs

@@ -121,6 +121,18 @@ public IEnumTypeDescriptor BindValuesExplicitly() =>
     public IEnumTypeDescriptor BindValuesImplicitly() =>
         BindValues(BindingBehavior.Implicit);
 
+    public IEnumTypeDescriptor NameComparer(IEqualityComparer<NameString> comparer)
+    {
+        Definition.NameComparer = comparer ?? throw new ArgumentNullException(nameof(comparer));
+        return this;
+    }
+
+    public IEnumTypeDescriptor ValueComparer(IEqualityComparer<object> comparer)
+    {
+        Definition.ValueComparer = comparer ?? throw new ArgumentNullException(nameof(comparer));
+        return this;
+    }
+
     [Obsolete("Use `Value`.")]
     public IEnumValueDescriptor Item<T>(T value) => Value<T>(value);
 

src/HotChocolate/Core/src/Types/Types/EnumType.Initialization.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
 using HotChocolate.Configuration;
 using HotChocolate.Internal;
 using HotChocolate.Properties;
@@ -14,8 +13,8 @@ namespace HotChocolate.Types;
 
 public partial class EnumType
 {
-    private readonly Dictionary<NameString, IEnumValue> _enumValues = new();
-    private readonly Dictionary<object, IEnumValue> _valueLookup = new();
+    private Dictionary<NameString, IEnumValue> _enumValues = default!;
+    private Dictionary<object, IEnumValue> _valueLookup = default!;
     private Action<IEnumTypeDescriptor>? _configure;
     private INamingConventions _naming = default!;
 
@@ -97,6 +96,9 @@ protected override void OnCompleteType(
     {
         base.OnCompleteType(context, definition);
 
+        _enumValues = new Dictionary<NameString, IEnumValue>(definition.NameComparer);
+        _valueLookup = new Dictionary<object, IEnumValue>(definition.ValueComparer);
+
         _naming = context.DescriptorContext.Naming;
         SyntaxNode = definition.SyntaxNode;
 
@@ -112,7 +114,7 @@ protected override void OnCompleteType(
             }
         }
 
-        if (!Values.Any())
+        if (Values.Count == 0)
         {
             context.ReportError(
                 SchemaErrorBuilder.New()