From 4c39b0711da6a1ff9e3802f7bac8f218687fb239 Mon Sep 17 00:00:00 2001
From: Steffen Agger <steffen.agger@gmail.com>
Date: Fri, 10 Jul 2020 16:10:07 +0200
Subject: [PATCH] toJSON checks for Realm.Object or Realm.Collection before
 calling toJSON recursively.

---
 lib/extensions.js | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/lib/extensions.js b/lib/extensions.js
index ec657673ef..a9d3252518 100644
--- a/lib/extensions.js
+++ b/lib/extensions.js
@@ -82,7 +82,8 @@ module.exports = function(realmConstructor, context) {
 
     Object.defineProperty(realmConstructor.Collection.prototype, "toJSON", {
         value: function (_, cache = new Map()) {
-            return this.map((item, index) => item.toJSON ? item.toJSON(index.toString(), cache) : item);
+            return this.map((item, index) =>
+                item instanceof realmConstructor.Object ? item.toJSON(index.toString(), cache) : item);
         },
 
         writable: true,
@@ -112,8 +113,10 @@ module.exports = function(realmConstructor, context) {
             Object.keys(this)
                 .concat(Object.keys(Object.getPrototypeOf(this)))
                 .forEach(key => {
-                    // TODO: check that we're dealing with a Realm type, before passing in cache?
-                    result[key] = this[key].toJSON ? this[key].toJSON(key, cache) : this[key];
+                    const value = this[key];
+                    result[key] = value instanceof realmConstructor.Object || value instanceof realmConstructor.Collection
+                        ? value.toJSON(key, cache)
+                        : value;
                 });
 
             return result;