Fix SchemaBuilder so it reads directives from extension types (#3667)

* Fix SchemaBuilder so it reads directives from extension types

* Update src/GraphQL/Utilities/SchemaBuilderExtensions.cs

src/GraphQL.Tests/Utilities/SchemaBuilderTests.cs

@@ -822,6 +822,29 @@ public void build_extension_type_out_of_order()
         type.Fields.Count.ShouldBe(2);
     }
 
+    [Fact]
+    public void reads_directives_from_types_or_extension_types()
+    {
+        var schema = Schema.For("""
+            extend type Query @directiveA {
+              field1: String
+            }
+
+            type Query @directiveB {
+              field2: String
+            }
+
+            directive @directiveA on OBJECT
+            directive @directiveB on OBJECT
+            """);
+
+        schema.Initialize();
+        var type = schema.AllTypes["Query"].ShouldNotBeNull();
+        var directives = type.GetAppliedDirectives()?.List.ShouldNotBeNull();
+        directives.Where(x => x.Name == "directiveA").ShouldHaveSingleItem();
+        directives.Where(x => x.Name == "directiveB").ShouldHaveSingleItem();
+    }
+
     [Fact]
     public async Task builds_with_customized_clr_type()
     {

src/GraphQL/Utilities/SchemaBuilderExtensions.cs

@@ -35,9 +35,18 @@ public static bool AstTypeHasFields(this IProvideMetadata type)
         {
             provider.WithMetadata(AST_METAFIELD, node); //TODO: remove?
 
-            if (node is IHasDirectivesNode ast && ast.Directives?.Count > 0)
+            if (node is IHasDirectivesNode ast)
+                provider.CopyDirectivesFrom(ast);
+
+            return provider;
+        }
+
+        public static TMetadataProvider CopyDirectivesFrom<TMetadataProvider>(this TMetadataProvider provider, IHasDirectivesNode node)
+            where TMetadataProvider : IProvideMetadata
+        {
+            if (node.Directives?.Count > 0)
             {
-                foreach (var directive in ast.Directives!)
+                foreach (var directive in node.Directives)
                 {
                     provider.ApplyDirective(directive!.Name.StringValue, d => //ISSUE:allocation
                     {
@@ -49,20 +58,23 @@ public static bool AstTypeHasFields(this IProvideMetadata type)
                     });
                 }
             }
-
             return provider;
         }
 
         public static bool HasExtensionAstTypes(this IProvideMetadata type)
         {
-            return GetExtensionAstTypes(type).Count > 0;
+            return type.HasMetadata(EXTENSION_AST_METAFIELD) && GetExtensionAstTypes(type).Count > 0;
         }
 
-        public static void AddExtensionAstType<T>(this IProvideMetadata type, T astType) where T : ASTNode
+        public static void AddExtensionAstType<T>(this IProvideMetadata type, T astType)
+            where T : ASTNode
         {
             var types = GetExtensionAstTypes(type);
             types.Add(astType);
             type.Metadata[EXTENSION_AST_METAFIELD] = types;
+
+            if (astType is IHasDirectivesNode ast)
+                type.CopyDirectivesFrom(ast);
         }
 
         public static List<ASTNode> GetExtensionAstTypes(this IProvideMetadata type)