From 61bb0969f3bba5487e6d559032c0a432f09ad4e4 Mon Sep 17 00:00:00 2001
From: Abdul Wasay <wasaya670@gmail.com>
Date: Tue, 25 Aug 2026 00:19:32 +0500
Subject: [PATCH] fix(runtime): prefer host type flags over mode bits in Stats
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Host stat payloads always carry isDirectory and isSymbolicLink, which reflect
what the VFS resolved, but Stats derived every type predicate from the mode
bits alone. On a backend whose mode bits can go stale — an NFS/EFS attribute
cache, for example — a regular file reporting the directory bit made
isDirectory() true, and callers that branch on it failed with EISDIR.

The type is now resolved once from the host flags, falling back to the mode
bits when a backend omits them, so a backend that sends no hints behaves
exactly as before. Dirent already used its explicit boolean this way.
---
 .../build-tools/bridge-src/builtins/fs.ts     | 32 +++++++++++++++----
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/packages/build-tools/bridge-src/builtins/fs.ts b/packages/build-tools/bridge-src/builtins/fs.ts
index e92133f795..93886f5e8d 100644
--- a/packages/build-tools/bridge-src/builtins/fs.ts
+++ b/packages/build-tools/bridge-src/builtins/fs.ts
@@ -15,6 +15,20 @@ var O_EXCL = 128;
 var O_TRUNC = 512;
 var O_APPEND = 1024;
 var KERNEL_POLLIN = 1;
+// Host stat payloads carry explicit `isDirectory` / `isSymbolicLink` flags that
+// reflect what the VFS actually resolved. Prefer them over the mode bits, which
+// can disagree on backends with stale attribute caches (e.g. NFS/EFS), and fall
+// back to the mode bits when a backend omits the hints.
+function resolveStatFormat(init) {
+  const fmt = init.mode & 61440;
+  const isDir = typeof init.isDirectory === "boolean" ? init.isDirectory : void 0;
+  const isLink = typeof init.isSymbolicLink === "boolean" ? init.isSymbolicLink : void 0;
+  if (isLink === true) return 40960;
+  if (isDir === true) return 16384;
+  if (isDir === false && fmt === 16384) return 32768;
+  if (isLink === false && fmt === 40960) return 32768;
+  return fmt;
+}
 var Stats = class {
   dev;
   ino;
@@ -56,27 +70,31 @@ var Stats = class {
     this.mtime = new Date(this.mtimeMs);
     this.ctime = new Date(this.ctimeMs);
     this.birthtime = new Date(this.birthtimeMs);
+    Object.defineProperty(this, "_typeFormat", {
+      value: resolveStatFormat(init),
+      enumerable: false
+    });
   }
   isFile() {
-    return (this.mode & 61440) === 32768;
+    return this._typeFormat === 32768;
   }
   isDirectory() {
-    return (this.mode & 61440) === 16384;
+    return this._typeFormat === 16384;
   }
   isSymbolicLink() {
-    return (this.mode & 61440) === 40960;
+    return this._typeFormat === 40960;
   }
   isBlockDevice() {
-    return (this.mode & 61440) === 24576;
+    return this._typeFormat === 24576;
   }
   isCharacterDevice() {
-    return (this.mode & 61440) === 8192;
+    return this._typeFormat === 8192;
   }
   isFIFO() {
-    return (this.mode & 61440) === 4096;
+    return this._typeFormat === 4096;
   }
   isSocket() {
-    return (this.mode & 61440) === 49152;
+    return this._typeFormat === 49152;
   }
 };
 var Dirent = class {