fix(nuxt): handle deleted cookies from CookieStore events (#28760)

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

@@ -103,9 +103,18 @@ export function useCookie<T = string | null | undefined> (name: string, _opts?:
     }
 
     if (store) {
+      /* event is of type CookieChangeEvent */
       const changeHandler = (event: any) => {
-        const cookie = event.changed.find((c: any) => c.name === name)
+        const changedCookie = event.changed.find((c: any) => c.name === name)
-        if (cookie) { handleChange({ value: cookie.value }) }
+        const removedCookie = event.deleted.find((c: any) => c.name === name)
+
+        if (changedCookie) {
+          handleChange({ value: changedCookie.value })
+        }
+
+        if (removedCookie) {
+          handleChange({ value: null })
+        }
       }
       store.addEventListener('change', changeHandler)
       if (hasScope) {

test/basic.test.ts

@@ -638,7 +638,7 @@ describe('nuxt composables', () => {
       },
     })
     const cookies = res.headers.get('set-cookie')
-    expect(cookies).toMatchInlineSnapshot('"set-in-plugin=true; Path=/, accessed-with-default-value=default; Path=/, set=set; Path=/, browser-set=set; Path=/, browser-set-to-null=; Max-Age=0; Path=/, browser-set-to-null-with-default=; Max-Age=0; Path=/, browser-object-default=%7B%22foo%22%3A%22bar%22%7D; Path=/"')
+    expect(cookies).toMatchInlineSnapshot('"set-in-plugin=true; Path=/, accessed-with-default-value=default; Path=/, set=set; Path=/, browser-set=set; Path=/, browser-set-to-null=; Max-Age=0; Path=/, browser-set-to-null-with-default=; Max-Age=0; Path=/, browser-object-default=%7B%22foo%22%3A%22bar%22%7D; Path=/, theCookie=show; Path=/"')
   })
   it('updates cookies when they are changed', async () => {
     const { page } = await renderPage('/cookies')
@@ -661,6 +661,26 @@ describe('nuxt composables', () => {
     await page.close()
   })
 
+  it('sets cookies in composable to null in all components', async () => {
+    const { page } = await renderPage('/cookies')
+    const parentBannerText = await page.locator('#parent-banner').textContent()
+    expect(parentBannerText).toContain('parent banner')
+
+    const childBannerText = await page.locator('#child-banner').innerText()
+    expect(childBannerText).toContain('child banner')
+
+    // Clear the composable cookie
+    await page.getByText('Toggle cookie banner').click()
+    await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 10)))
+
+    const parentBannerAfterToggle = await page.locator('#parent-banner').isVisible()
+    expect(parentBannerAfterToggle).toBe(false)
+
+    const childBannerAfterToggle = await page.locator('#child-banner').isVisible()
+    expect(childBannerAfterToggle).toBe(false)
+    await page.close()
+  })
+
   it('supports onPrehydrate', async () => {
     const html = await $fetch<string>('/composables/on-prehydrate') as string
     /**

test/fixtures/basic/components/ComponentUsingCookie.vue

@@ -0,0 +1,14 @@
+<script setup>
+import { useCookieManager } from '../composables/cookie-manager'
+
+const { showCookieBanner } = useCookieManager()
+</script>
+
+<template>
+  <div
+    v-if="showCookieBanner"
+    id="child-banner"
+  >
+    child banner
+  </div>
+</template>

test/fixtures/basic/composables/cookie-manager.ts

@@ -0,0 +1,18 @@
+export function useCookieManager () {
+  const theCookie = useCookie<null | string>('theCookie', {
+    default: () => 'show',
+  })
+
+  const showCookieBanner = computed(() => {
+    return theCookie.value === 'show'
+  })
+
+  function toggle () {
+    theCookie.value = theCookie.value === 'show' ? null : 'show'
+  }
+
+  return {
+    showCookieBanner,
+    toggle,
+  }
+}

test/fixtures/basic/pages/cookies.vue

@@ -1,4 +1,7 @@
 <script setup lang="ts">
+import CookieComponent from '../components/ComponentUsingCookie.vue'
+import { useCookieManager } from '../composables/cookie-manager'
+
 useCookie('accessed-but-not-used')
 useCookie('accessed-with-default-value', { default: () => 'default' })
 useCookie('set').value = 'set'
@@ -25,6 +28,8 @@ function changeCookie () {
     objectCookie.value!.foo = 'baz'
   }
 }
+
+const { showCookieBanner, toggle } = useCookieManager()
 </script>
 
 <template>
@@ -38,5 +43,16 @@ function changeCookie () {
     <button @click="refreshCookie('browser-object-default')">
       Refresh cookie
     </button>
+
+    <CookieComponent />
+    <div
+      v-if="showCookieBanner"
+      id="parent-banner"
+    >
+      parent banner
+    </div>
+    <button @click="toggle">
+      Toggle cookie banner
+    </button>
   </div>
 </template>