Support @include/@Skip for non-nullable fields (#7918)

Author: timward60

src/HotChocolate/Core/src/Types/Types/Extensions/DirectiveCollectionExtensions.cs

@@ -105,11 +105,11 @@ private static IValueNode GetIfArgumentValue(DirectiveNode directive)
         throw ThrowHelper.MissingIfArgument(directive);
     }
 
-    private static DirectiveNode? GetSkipDirectiveNode(
+    internal static DirectiveNode? GetSkipDirectiveNode(
         this IReadOnlyList<DirectiveNode> directives)
         => GetDirectiveNode(directives, WellKnownDirectives.Skip);
 
-    private static DirectiveNode? GetIncludeDirectiveNode(
+    internal static DirectiveNode? GetIncludeDirectiveNode(
         this IReadOnlyList<DirectiveNode> directives)
         => GetDirectiveNode(directives, WellKnownDirectives.Include);
 

src/StrawberryShake/CodeGeneration/src/CodeGeneration/Descriptors/TypeDescriptors/PropertyKind.cs

@@ -19,4 +19,9 @@ public enum PropertyKind
     /// A non-null field that is deferred.
     /// </summary>
     DeferredField,
+
+    /// <summary>
+    /// A non-null field that is included or skipped conditionally.
+    /// </summary>
+    SkipOrIncludeField
 }

src/StrawberryShake/CodeGeneration/src/CodeGeneration/Mappers/TypeDescriptorMapper.cs

@@ -375,6 +375,12 @@ private static void CollectClassesThatImplementInterface(
         }
     }
 
+    private static bool IncludeOrSkipDirective(OutputFieldModel field)
+    {
+        return field.SyntaxNode.Directives.GetIncludeDirectiveNode() is not null ||
+            field.SyntaxNode.Directives.GetSkipDirectiveNode() is not null;
+    }
+
     private static void AddProperties(
         ClientModel model,
         Dictionary<string, TypeDescriptorModel> typeDescriptors,
@@ -388,6 +394,7 @@ private static void AddProperties(
             {
                 INamedTypeDescriptor? fieldType;
                 var namedType = field.Type.NamedType();
+                var includeOrSkipDirective = IncludeOrSkipDirective(field);
 
                 if (namedType.IsScalarType() || namedType.IsEnumType())
                 {
@@ -402,14 +409,19 @@ private static void AddProperties(
                         typeDescriptors);
                 }
 
+                var propertyKind = includeOrSkipDirective
+                    ? PropertyKind.SkipOrIncludeField
+                    : PropertyKind.Field;
                 properties.Add(
                     new PropertyDescriptor(
                         field.Name,
                         field.ResponseName,
                         BuildFieldType(
                             field.Type,
-                            fieldType),
-                        field.Description));
+                            fieldType,
+                            propertyKind),
+                        field.Description,
+                        propertyKind));
             }
 
             typeDescriptorModel.Descriptor.CompleteProperties(properties);
@@ -478,10 +490,18 @@ private static INamedTypeDescriptor GetFieldTypeDescriptor(
 
     private static ITypeDescriptor BuildFieldType(
         this IType original,
-        INamedTypeDescriptor namedTypeDescriptor)
+        INamedTypeDescriptor namedTypeDescriptor,
+        PropertyKind kind = PropertyKind.Field)
     {
         if (original is NonNullType nnt)
         {
+            if (kind == PropertyKind.SkipOrIncludeField)
+            {
+                return BuildFieldType(
+                    nnt.Type,
+                    namedTypeDescriptor);
+            }
+
             return new NonNullTypeDescriptor(
                 BuildFieldType(
                     nnt.Type,