From 2afe69e236550eb8a3e89d76bee1f77bf0133982 Mon Sep 17 00:00:00 2001
From: Minh Nguyen <2852660+NMinhNguyen@users.noreply.github.com>
Date: Fri, 20 May 2022 14:27:38 +0100
Subject: [PATCH] fix(fetch): replace `instanceof FormData` check (#1457)

---
 lib/fetch/body.js      | 2 +-
 lib/fetch/formdata.js  | 2 ++
 test/fetch/formdata.js | 6 ++++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/fetch/body.js b/lib/fetch/body.js
index c02f79f97b4..415e4ea34da 100644
--- a/lib/fetch/body.js
+++ b/lib/fetch/body.js
@@ -71,7 +71,7 @@ function extractBody (object, keepalive = false) {
 
     // Set source to a copy of the bytes held by object.
     source = new Uint8Array(object)
-  } else if (object instanceof FormData || util.isFormDataLike(object)) {
+  } else if (util.isFormDataLike(object)) {
     const boundary = '----formdata-undici-' + Math.random()
     const prefix = `--${boundary}\r\nContent-Disposition: form-data`
 
diff --git a/lib/fetch/formdata.js b/lib/fetch/formdata.js
index 0a84f1f384b..e12d2b42bd2 100644
--- a/lib/fetch/formdata.js
+++ b/lib/fetch/formdata.js
@@ -6,6 +6,8 @@ const { File, FileLike } = require('./file')
 const { Blob } = require('buffer')
 
 class FormData {
+  static name = 'FormData'
+
   constructor (...args) {
     if (args.length > 0 && !(args[0]?.constructor?.name === 'HTMLFormElement')) {
       throw new TypeError(
diff --git a/test/fetch/formdata.js b/test/fetch/formdata.js
index 9b7f3d4a096..0563de0720c 100644
--- a/test/fetch/formdata.js
+++ b/test/fetch/formdata.js
@@ -216,3 +216,9 @@ test('formData toStringTag', (t) => {
   t.equal(FormData.prototype[Symbol.toStringTag], 'FormData')
   t.end()
 })
+
+test('formData.constructor.name', (t) => {
+  const form = new FormData()
+  t.equal(form.constructor.name, 'FormData')
+  t.end()
+})