From 0fa55c43b2514e852771ce8df0f12e0cdd97a608 Mon Sep 17 00:00:00 2001
From: nanami-0713 <312767031+nanami-0713@users.noreply.github.com>
Date: Sun, 27 Sep 2026 21:05:28 +0800
Subject: [PATCH] fix(jsdom): unwrap the Blob implementation via implForWrapper
 to support jsdom 30.1

jsdom 30.1 moved the implementation object from the hidden Symbol(impl)
own property into a private class field, so the symbol scan in
createCompatUtils finds nothing and every makeCompatBlob caller
(URL.createObjectURL, Request/FormData bodies) throws
"Cannot read properties of undefined (reading '_bytes')".

Resolve the implementation with jsdom's own implForWrapper instead
(jsdom has no exports map, the subpath can be required directly),
keeping the symbol scan as a fallback for older layouts.
---
 packages/vitest/src/integrations/env/jsdom.ts | 29 ++++++++++++++++++-
 test/unit/test/environments/jsdom.spec.ts     |  2 ++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/packages/vitest/src/integrations/env/jsdom.ts b/packages/vitest/src/integrations/env/jsdom.ts
index ffa661180d86..15a073bc80e0 100644
--- a/packages/vitest/src/integrations/env/jsdom.ts
+++ b/packages/vitest/src/integrations/env/jsdom.ts
@@ -1,6 +1,7 @@
 import type { ConstructorOptions, DOMWindow, VirtualConsole as IVirtualConsole } from 'jsdom'
 import type { Environment } from '../../types/environment'
 import type { JSDOMOptions } from '../../types/jsdom-options'
+import { createRequire } from 'node:module'
 import { URL as NodeURL } from 'node:url'
 import { populateGlobal } from './utils'
 
@@ -306,6 +307,11 @@ function createCompatUtils(window: DOMWindow): CompatUtils {
   const implSymbol = Object.getOwnPropertySymbols(
     Object.getOwnPropertyDescriptors(new window.Blob()),
   )[0]
+  // jsdom 30.1 moved the implementation from the `Symbol(impl)` own property
+  // into a private class field, so `implSymbol` is `undefined` there and
+  // `blob[implSymbol]` cannot unwrap the wrapper anymore;
+  // jsdom's own `implForWrapper` can unwrap both layouts
+  const implForWrapper = getImplForWrapper()
   const utils = {
     window,
     makeCompatFormData(formData: FormData) {
@@ -321,7 +327,7 @@ function createCompatUtils(window: DOMWindow): CompatUtils {
       return nodeFormData
     },
     makeCompatBlob(blob: Blob) {
-      const impl = (blob as any)[implSymbol]
+      const impl = (implForWrapper?.(blob) ?? (blob as any)[implSymbol]) as any
       // jsdom 28 renamed `_buffer` to `_bytes`
       return new NodeBlob_([impl._bytes ?? impl._buffer], { type: blob.type })
     },
@@ -329,6 +335,27 @@ function createCompatUtils(window: DOMWindow): CompatUtils {
   return utils
 }
 
+function getImplForWrapper(): ((wrapper: object) => unknown) | undefined {
+  const require = createRequire(import.meta.url)
+  // jsdom 30.1+ exports `implForWrapper` from the new subpath, older
+  // versions from the old one; jsdom has no `exports` map, so both
+  // subpaths can be required directly
+  const subpaths = [
+    'jsdom/lib/generated/idl/utils.js',
+    'jsdom/lib/jsdom/living/generated/utils.js',
+  ]
+  for (const subpath of subpaths) {
+    try {
+      const utils = require(subpath)
+      if (typeof utils?.implForWrapper === 'function') {
+        return utils.implForWrapper
+      }
+    }
+    catch {}
+  }
+  return undefined
+}
+
 function patchAddEventListener(window: DOMWindow) {
   const abortControllers = new WeakMap<AbortSignal, AbortController>()
   const JSDOMAbortSignal = window.AbortSignal
diff --git a/test/unit/test/environments/jsdom.spec.ts b/test/unit/test/environments/jsdom.spec.ts
index b61a0af842db..ae348b798aa1 100644
--- a/test/unit/test/environments/jsdom.spec.ts
+++ b/test/unit/test/environments/jsdom.spec.ts
@@ -324,6 +324,8 @@ test('URL.createObjectUrl works properly', () => {
   expect(() => {
     URL.createObjectURL(new File([], 'name.js'))
   }).not.toThrow()
+  expect(URL.createObjectURL(new Blob(['hello']))).toMatch(/^blob:/)
+  expect(URL.createObjectURL(new File(['hello'], 'name.js'))).toMatch(/^blob:/)
 })
 
 test('compat classes preserve their .name property', () => {