From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shelley Vohr <shelley.vohr@gmail.com>
Date: Sat, 25 Oct 2025 11:06:10 +0200
Subject: lib: check SharedArrayBuffer existence in fast-utf8-stream

After https://github.com/nodejs/node/pull/58897 calling
Object.entries on fs will lazy-load fast-utf8-stream, which uses
SharedArrayBuffer without checking for its existence first. It
won't exist in the renderer process and will throw
'SharedArrayBuffer is not a constructor'. Refactor to check
for SharedArrayBuffer first.

This should be upstreamed to Node.js

diff --git a/lib/internal/streams/fast-utf8-stream.js b/lib/internal/streams/fast-utf8-stream.js
index 3bfcc494d17b5cc4c9f494fab4aff4f0d68d2287..241a6b05e84f8e79b8c9b93abfda5562c2e35e9e 100644
--- a/lib/internal/streams/fast-utf8-stream.js
+++ b/lib/internal/streams/fast-utf8-stream.js
@@ -49,7 +49,8 @@ const {
 const BUSY_WRITE_TIMEOUT = 100;
 const kEmptyBuffer = Buffer.allocUnsafe(0);
 
-const kNil = new Int32Array(new SharedArrayBuffer(4));
+const haveSAB = typeof SharedArrayBuffer !== 'undefined';
+const kNil = haveSAB ? new Int32Array(new SharedArrayBuffer(4)) : null;
 
 function sleep(ms) {
   // Also filters out NaN, non-number types, including empty strings, but allows bigints
@@ -59,10 +60,14 @@ function sleep(ms) {
       throw new ERR_INVALID_ARG_TYPE('ms', ['number', 'bigint'], ms);
     }
     throw new ERR_INVALID_ARG_VALUE.RangeError('ms', ms,
-                                               'must be a number greater than 0 and less than Infinity');
+      'must be a number greater than 0 and less than Infinity');
+  }
+  if (haveSAB) {
+    AtomicsWait(kNil, 0, 0, Number(ms));
+  } else {
+    const { sleep: _sleep } = internalBinding('util');
+    _sleep(ms);
   }
-
-  AtomicsWait(kNil, 0, 0, Number(ms));
 }
 
 // 16 KB. Don't write more than docker buffer size.