From c1fc0860de75dbbbc031b93c08520f1a1fd45ba1 Mon Sep 17 00:00:00 2001
From: FFranck <franck.franck@mongodb.com>
Date: Mon, 26 Jul 2021 17:33:57 +0200
Subject: [PATCH] Fix for Set prototype resolution (#3843)

Fixed issue that could result in stack overflow when using Set iterators.
---
 CHANGELOG.md              | 4 ++--
 lib/collection-methods.js | 4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c479653809..2798138cd3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,8 +4,8 @@ x.x.x Release notes (yyyy-MM-dd)
 * None.
 
 ### Fixed
-* Fixed TypeScript definition of `Realm.Dictionary.remove()`. (since v10.6.0)
-* Fixed Realm.Object#toJSON as it threw "Right-hand side of 'instanceof' is not an object". (since v10.6.0)
+* Fix TypeScript definition of `Realm.Dictionary.remove()`. (since v10.6.0)
+* Fixed `Realm not defined` error experienced when using `Realm.Set` iterators under Jest
 
 ### Compatibility
 * MongoDB Realm Cloud.
diff --git a/lib/collection-methods.js b/lib/collection-methods.js
index 76b56cbb18..0e1e395b3c 100644
--- a/lib/collection-methods.js
+++ b/lib/collection-methods.js
@@ -55,7 +55,9 @@ Object.defineProperty(iteratorPrototype, Symbol.iterator, {
 
 ["entries", "keys", "values"].forEach(function (methodName) {
   var method = function () {
-    const isSet = this instanceof Realm.Set;
+    // checks for Set datatype.  Required for compatibility with node.js, Jest, and RN
+    // instanceof Set is not performing correctly in Jest tests, so we need to use an alternate method
+    const isSet = (this.constructor && this.constructor.name === "Set") || this instanceof Realm.Set;
     var self = this.type === "object" || isSet ? this.snapshot() : this;
     var index = 0;