From 53ea744a59e55d28ee5190e37f358afa87fe14da Mon Sep 17 00:00:00 2001
From: Timur Mashara <timur@metabase.com>
Date: Fri, 24 Jul 2026 11:04:41 +0200
Subject: [PATCH] Guard syntax highlighting when hljs fails to load

highlight.js is loaded from cdnjs, which is unreliable/blocked in some
regions (notably China). When it fails to load, syntax-highlight.js threw
ReferenceError: hljs is not defined on DOMContentLoaded (Sentry
METABASE-COM-4W3, 10k+ events). Bail out early when hljs is missing so
code blocks render unhighlighted instead of throwing.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 js/syntax-highlight.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/js/syntax-highlight.js b/js/syntax-highlight.js
index 6655cc6bc4..f6207749ca 100644
--- a/js/syntax-highlight.js
+++ b/js/syntax-highlight.js
@@ -26,6 +26,10 @@ window.addEventListener("DOMContentLoaded", () => {
       }
     });
 
+    if (typeof hljs === "undefined") {
+      return;
+    }
+
     hljs.configure({ ignoreUnescapedHTML: true });
 
     hljs.highlightAll();