fix(nuxt): don't share object between raw cookie and cookie ref (#25255)

packages/nuxt/src/app/composables/cookie.ts

@@ -61,6 +61,8 @@ export function useCookie<T = string | null | undefined> (name: string, _opts?:
     const callback = () => {
       if (opts.readonly || isEqual(cookie.value, cookies[name])) { return }
       writeClientCookie(name, cookie.value, opts as CookieSerializeOptions)
+
+      cookies[name] = klona(cookie.value)
       channel?.postMessage(opts.encode(cookie.value as T))
     }
 
@@ -107,7 +109,7 @@ export function useCookie<T = string | null | undefined> (name: string, _opts?:
   return cookie as CookieRef<T>
 }
 
-function readRawCookies (opts: CookieOptions = {}): Record<string, string> | undefined {
+function readRawCookies (opts: CookieOptions = {}): Record<string, unknown> | undefined {
   if (import.meta.server) {
     return parse(getRequestHeader(useRequestEvent(), 'cookie') || '', opts)
   } else if (import.meta.client) {

test/basic.test.ts

@@ -501,6 +501,8 @@ describe('nuxt composables', () => {
     expect(await extractCookie()).toEqual({ foo: 'bar' })
     await page.getByRole('button').click()
     expect(await extractCookie()).toEqual({ foo: 'baz' })
+    await page.getByRole('button').click()
+    expect(await extractCookie()).toEqual({ foo: 'bar' })
     await page.close()
   })
 })

test/fixtures/basic/pages/cookies.vue

@@ -20,7 +20,7 @@ const objectCookie = useCookie('browser-object-default', {
   <div>
     <div>cookies testing page</div>
     <pre>{{ objectCookie }}</pre>
-    <button @click="objectCookie.foo = 'baz'">
+    <button @click="objectCookie.foo === 'baz' ? objectCookie.foo = 'bar' : objectCookie.foo = 'baz'">
       Change cookie
     </button>
   </div>