From 672491db34b5575d2abb1c3f91382bc1f45ae7b7 Mon Sep 17 00:00:00 2001
From: Shiwaangee <shiwaangee@gmail.com>
Date: Sat, 14 Feb 2026 21:12:56 +0530
Subject: [PATCH] fix: safe FormData detection for WeChat Mini Program (#7306)
 (#7324)

Co-authored-by: Jay <jasonsaayman@gmail.com>
---
 lib/utils.js | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/lib/utils.js b/lib/utils.js
index 239a3d74..0ef9c0b5 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -220,17 +220,27 @@ const isStream = (val) => isObject(val) && isFunction(val.pipe);
  *
  * @returns {boolean} True if value is an FormData, otherwise false
  */
+function getGlobal() {
+  if (typeof globalThis !== 'undefined') return globalThis;
+  if (typeof self !== 'undefined') return self;
+  if (typeof window !== 'undefined') return window;
+  if (typeof global !== 'undefined') return global;
+  return {};
+}
+
+const G = getGlobal();
+const FormDataCtor = typeof G.FormData !== 'undefined' ? G.FormData : undefined;
+
 const isFormData = (thing) => {
   let kind;
-  return (
-    thing &&
-    ((typeof FormData === 'function' && thing instanceof FormData) ||
-      (isFunction(thing.append) &&
-        ((kind = kindOf(thing)) === 'formdata' ||
-          // detect form-data instance
-          (kind === 'object' &&
-            isFunction(thing.toString) &&
-            thing.toString() === '[object FormData]'))))
+  return thing && (
+    (FormDataCtor && thing instanceof FormDataCtor) || (
+      isFunction(thing.append) && (
+        (kind = kindOf(thing)) === 'formdata' ||
+        // detect form-data instance
+        (kind === 'object' && isFunction(thing.toString) && thing.toString() === '[object FormData]')
+      )
+    )
   );
 };