fix(cache): add value == and hashCode to lazy cache map, fix traversal

packages/graphql/lib/src/cache/lazy_cache_map.dart

@@ -1,4 +1,5 @@
 import 'dart:core';
+import 'package:quiver/core.dart' show hash3;
 
 import 'package:meta/meta.dart';
 
@@ -33,6 +34,14 @@ class LazyCacheMap extends LazyDereferencingMap {
     }
     return result;
   }
+
+  int get hashCode => hash3(_data, _dereference, cacheState);
+
+  bool operator ==(Object other) =>
+      other is LazyCacheMap &&
+      other._data == _data &&
+      other._dereference == _dereference &&
+      other.cacheState == cacheState;
 }
 
 /// Unwrap a given Object that could possibly be a lazy map

packages/graphql/lib/src/utilities/traverse.dart

@@ -13,35 +13,35 @@ class Traversal {
     this.transformSideEffect,
     this.seenObjects,
   }) {
-    seenObjects ??= HashSet<int>();
+    seenObjects ??= HashSet<Object>();
   }
 
   Transform transform;
 
   /// An optional side effect to call when a node is transformed.
   SideEffect transformSideEffect;
-  HashSet<int> seenObjects;
+  HashSet<Object> seenObjects;
 
-  bool hasAlreadySeen(Object node) {
-    final bool wasAdded = seenObjects.add(node.hashCode);
+  bool alreadySeen(Object node) {
+    final bool wasAdded = seenObjects.add(node);
     return !wasAdded;
   }
 
   /// Traverse only the values of the given map
   Map<String, Object> traverseValues(Map<String, Object> node) {
     return node.map<String, Object>(
       (String key, Object value) => MapEntry<String, Object>(
-            key,
-            traverse(value),
-          ),
+        key,
+        traverse(value),
+      ),
     );
   }
 
   // Attempts to apply the transform to every leaf of the data structure recursively.
   // Stops recursing when a node is transformed (returns non-null)
   Object traverse(Object node) {
     final Object transformed = transform(node);
-    if (hasAlreadySeen(node)) {
+    if (alreadySeen(node)) {
       return transformed ?? node;
     }
     if (transformed != null) {

packages/graphql/pubspec.yaml

@@ -18,6 +18,7 @@ dependencies:
   graphql_parser: ^1.1.3
   rxdart: ^0.22.0
   websocket: ^0.0.5
+  quiver: '>=2.0.0 <3.0.0'
 dev_dependencies:
   pedantic: <=1.7.99
   mockito: ^4.0.0