From fa112defe8e456a7ee8e19eb9a55579de5820061 Mon Sep 17 00:00:00 2001
From: Juan Manuel Castillo <jm.castillo12@uniandes.edu.co>
Date: Mon, 25 Oct 2021 14:30:06 +0000
Subject: [PATCH] add interfaces to InterfaceTypeDefinitionNode
 (https://github.com/gql-dart/gql/issues/269)

---
 gql/lib/src/ast/ast.dart          | 3 +++
 gql/lib/src/language/parser.dart  | 2 ++
 gql/lib/src/language/printer.dart | 1 +
 3 files changed, 6 insertions(+)

diff --git a/gql/lib/src/ast/ast.dart b/gql/lib/src/ast/ast.dart
index a71354e3..c29507e0 100644
--- a/gql/lib/src/ast/ast.dart
+++ b/gql/lib/src/ast/ast.dart
@@ -811,11 +811,13 @@ class InputValueDefinitionNode extends Node {
 
 class InterfaceTypeDefinitionNode extends TypeDefinitionNode {
   final List<FieldDefinitionNode> fields;
+  final List<NamedTypeNode> interfaces;
 
   const InterfaceTypeDefinitionNode({
     this.fields = const [],
     StringValueNode? description,
     required NameNode name,
+    this.interfaces = const [],
     List<DirectiveNode> directives = const [],
     FileSpan? span,
   }) : super(
@@ -833,6 +835,7 @@ class InterfaceTypeDefinitionNode extends TypeDefinitionNode {
         name,
         description,
         directives,
+        interfaces,
         fields,
       ];
 }
diff --git a/gql/lib/src/language/parser.dart b/gql/lib/src/language/parser.dart
index d4882479..98777079 100644
--- a/gql/lib/src/language/parser.dart
+++ b/gql/lib/src/language/parser.dart
@@ -740,12 +740,14 @@ class _Parser {
     final description = _parseDescription();
     _expectKeyword("interface");
     final name = _parseName("Expected an interface name");
+    final interfaces = _parseImplementsInterfaces();
     final directives = _parseDirectives(isConst: true);
     final fields = _parseFieldsDefinition();
 
     return InterfaceTypeDefinitionNode(
       description: description,
       name: name,
+      interfaces: interfaces,
       directives: directives,
       fields: fields,
     );
diff --git a/gql/lib/src/language/printer.dart b/gql/lib/src/language/printer.dart
index e50b1d1d..b602127c 100644
--- a/gql/lib/src/language/printer.dart
+++ b/gql/lib/src/language/printer.dart
@@ -435,6 +435,7 @@ class _PrintVisitor extends Visitor<String> {
         " ",
         node.name.accept(this),
         " ",
+        visitImplementsSetNode(node.interfaces),
         visitDirectiveSetNode(node.directives),
         visitFieldSetNode(node.fields),
       ].join();