From 25f7a16a6eccbfa8d857977dcf1f23fb36b830b5 Mon Sep 17 00:00:00 2001
From: Hitesh Khandelwal <hkk12369@gmail.com>
Date: Mon, 13 Jun 2022 08:36:15 +0530
Subject: [PATCH] perf(ssr): improve isComment check (#6078)

---
 packages/server-renderer/src/helpers/ssrRenderSlot.ts | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/server-renderer/src/helpers/ssrRenderSlot.ts b/packages/server-renderer/src/helpers/ssrRenderSlot.ts
index fbe7266b2a1..ea1e7e94106 100644
--- a/packages/server-renderer/src/helpers/ssrRenderSlot.ts
+++ b/packages/server-renderer/src/helpers/ssrRenderSlot.ts
@@ -87,11 +87,11 @@ export function ssrRenderSlotInner(
   }
 }
 
+const commentTestRE = /^<!--.*-->$/s
 const commentRE = /<!--[^]*?-->/gm
 function isComment(item: SSRBufferItem) {
-  return (
-    typeof item === 'string' &&
-    commentRE.test(item) &&
-    !item.replace(commentRE, '').trim()
-  )
+  if (typeof item !== 'string' || !commentTestRE.test(item)) return false
+  // if item is '<!---->' or '<!--[-->' or '<!--]-->', return true directly
+  if (item.length <= 8) return true
+  return !item.replace(commentRE, '').trim()
 }