From b92ef84a283a3e8425775db5469d41c4a5ad38e6 Mon Sep 17 00:00:00 2001
From: Jan Lenoch <jan.lenoch@hotmail.cz>
Date: Tue, 30 Oct 2018 12:19:20 +0100
Subject: [PATCH] Handle circular references when serializing node content

---
 package.json     |  2 +-
 src/normalize.js | 19 ++++++++++++++++++-
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/package.json b/package.json
index 9eeb17cd..8c4db2cd 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "gatsby-source-kentico-cloud",
   "description": "Gatsby source plugin for Kentico Cloud",
-  "version": "2.0.0-beta1",
+  "version": "2.0.0-beta2",
   "repository": {
     "type": "git",
     "url": "https://github.com/Kentico/gatsby-source-kentico-cloud"
diff --git a/src/normalize.js b/src/normalize.js
index e341f1f4..85ffdd7e 100644
--- a/src/normalize.js
+++ b/src/normalize.js
@@ -242,7 +242,24 @@ of valid objects.`);
 const createKcArtifactNode =
   (nodeId, kcArtifact, artifactKind, typeName = ``,
       additionalNodeData = null) => {
-    const nodeContent = JSON.stringify(kcArtifact);
+    let processedProperties = [];
+
+    // Handle circular references when serializing.
+    const nodeContent = JSON.stringify(kcArtifact, (key, value) =>{
+      if (typeof value === `object` && value !== null) {
+        if (processedProperties.indexOf(value) !== -1) {
+          try {
+            return JSON.parse(JSON.stringify(value));
+          } catch (error) {
+            return;
+          }
+        }
+        processedProperties.push(value);
+      }
+      return value;
+    });
+
+    processedProperties = null;
 
     const nodeContentDigest = crypto
         .createHash(`md5`)