feat(nuxt): allow server islands to manipulate head (#27987)

package.json

@@ -63,6 +63,7 @@
     "@types/node": "20.16.1",
     "@types/semver": "7.5.8",
     "@unhead/schema": "1.10.0",
+    "@unhead/vue": "^1.10.0",
     "@vitejs/plugin-vue": "5.1.2",
     "@vitest/coverage-v8": "2.0.5",
     "@vue/test-utils": "2.4.6",

packages/nuxt/src/app/components/island-renderer.ts

@@ -1,6 +1,7 @@
 import type { defineAsyncComponent } from 'vue'
 import { createVNode, defineComponent, onErrorCaptured } from 'vue'
 
+import { injectHead } from '@unhead/vue'
 import { createError } from '../composables/error'
 
 // @ts-expect-error virtual file
@@ -14,6 +15,10 @@ export default defineComponent({
     },
   },
   setup (props) {
+    // reset head - we don't want to have any head tags from plugin or anywhere else.
+    const head = injectHead()
+    head.headEntries().splice(0, head.headEntries().length)
+
     const component = islandComponents[props.context.name] as ReturnType<typeof defineAsyncComponent>
 
     if (!component) {

packages/nuxt/src/app/components/nuxt-island.ts

@@ -3,7 +3,7 @@ import { Fragment, Teleport, computed, createStaticVNode, createVNode, defineCom
 import { debounce } from 'perfect-debounce'
 import { hash } from 'ohash'
 import { appendResponseHeader } from 'h3'
-import { useHead } from '@unhead/vue'
+import { injectHead } from '@unhead/vue'
 import { randomUUID } from 'uncrypto'
 import { joinURL, withQuery } from 'ufo'
 import type { FetchResponse } from 'ofetch'
@@ -96,7 +96,7 @@ export default defineComponent({
       if (result.props) { toRevive.props = result.props }
       if (result.slots) { toRevive.slots = result.slots }
       if (result.components) { toRevive.components = result.components }
-
+      if (result.head) { toRevive.head = result.head }
       nuxtApp.payload.data[key] = {
         __nuxt_island: {
           key,
@@ -158,8 +158,7 @@ export default defineComponent({
       return html
     })
 
-    const cHead = ref<Record<'link' | 'style', Array<Record<string, string>>>>({ link: [], style: [] })
+    const head = injectHead()
-    useHead(cHead)
 
     async function _fetchComponent (force = false) {
       const key = `${props.name}_${hashId.value}`
@@ -199,8 +198,7 @@ export default defineComponent({
       }
       try {
         const res: NuxtIslandResponse = await nuxtApp[pKey][uid.value]
-        cHead.value.link = res.head.link
+
-        cHead.value.style = res.head.style
         ssrHTML.value = res.html.replaceAll(DATA_ISLAND_UID_RE, `data-island-uid="${uid.value}"`)
         key.value++
         error.value = null
@@ -248,6 +246,13 @@ export default defineComponent({
       await loadComponents(props.source, payloads.components)
     }
 
+    if (import.meta.server || nuxtApp.isHydrating) {
+      // re-push head into active head instance
+      (nuxtApp.payload.data[`${props.name}_${hashId.value}`] as NuxtIslandResponse)?.head?.forEach((h) => {
+        head.push(h)
+      })
+    }
+
     return (_ctx: any, _cache: any) => {
       if (!html.value || error.value) {
         return [slots.fallback?.({ error: error.value }) ?? createVNode('div')]

packages/nuxt/src/app/plugins/revive-payload.client.ts

@@ -31,11 +31,6 @@ if (componentIslands) {
     }
     return {
       html: '',
-      state: {},
-      head: {
-        link: [],
-        style: [],
-      },
       ...result,
     }
   }

packages/nuxt/src/core/runtime/nitro/renderer.ts

@@ -16,11 +16,10 @@ import { stringify, uneval } from 'devalue'
 import destr from 'destr'
 import { getQuery as getURLQuery, joinURL, withoutTrailingSlash } from 'ufo'
 import { renderToString as _renderToString } from 'vue/server-renderer'
-import { hash } from 'ohash'
 import { propsToString, renderSSRHead } from '@unhead/ssr'
-import type { HeadEntryOptions } from '@unhead/schema'
+import type { Head, HeadEntryOptions } from '@unhead/schema'
 import type { Link, Script, Style } from '@unhead/vue'
-import { createServerHead } from '@unhead/vue'
+import { createServerHead, resolveUnrefHeadInput } from '@unhead/vue'
 
 import { defineRenderHandler, getRouteRules, useNitroApp, useRuntimeConfig, useStorage } from 'nitro/runtime'
 
@@ -79,10 +78,7 @@ export interface NuxtIslandContext {
 export interface NuxtIslandResponse {
   id?: string
   html: string
-  head: {
+  head: Head[]
-    link: (Record<string, string>)[]
-    style: ({ innerHTML: string, key: string })[]
-  }
   props?: Record<string, Record<string, any>>
   components?: Record<string, NuxtIslandClientResponse>
   slots?: Record<string, NuxtIslandSlotResponse>
@@ -288,6 +284,7 @@ export default defineRenderHandler(async (event): Promise<Partial<RenderResponse
   const head = createServerHead({
     plugins: unheadPlugins,
   })
+
   // needed for hash hydration plugin to work
   const headEntryOptions: HeadEntryOptions = { mode: 'server' }
   if (!isRenderingIsland) {
@@ -394,7 +391,9 @@ export default defineRenderHandler(async (event): Promise<Partial<RenderResponse
   }
 
   // 2. Styles
+  if (inlinedStyles.length) {
     head.push({ style: inlinedStyles })
+  }
   if (!isRenderingIsland || import.meta.dev) {
     const link: Link[] = []
     for (const style in styles) {
@@ -411,8 +410,10 @@ export default defineRenderHandler(async (event): Promise<Partial<RenderResponse
         link.push({ rel: 'stylesheet', href: renderer.rendererContext.buildAssetsURL(resource.file) })
       }
     }
+    if (link.length) {
       head.push({ link }, headEntryOptions)
     }
+  }
 
   if (!NO_SCRIPTS && !isRenderingIsland) {
     // 3. Resource Hints
@@ -460,20 +461,9 @@ export default defineRenderHandler(async (event): Promise<Partial<RenderResponse
 
   // Response for component islands
   if (isRenderingIsland && islandContext) {
-    const islandHead: NuxtIslandResponse['head'] = {
-      link: [],
-      style: [],
-    }
-    for (const tag of await head.resolveTags()) {
-      if (tag.tag === 'link') {
-        islandHead.link.push({ key: 'island-link-' + hash(tag.props), ...tag.props })
-      } else if (tag.tag === 'style' && tag.innerHTML) {
-        islandHead.style.push({ key: 'island-style-' + hash(tag.innerHTML), innerHTML: tag.innerHTML })
-      }
-    }
     const islandResponse: NuxtIslandResponse = {
       id: islandContext.id,
-      head: islandHead,
+      head: (head.headEntries().map(h => resolveUnrefHeadInput(h.input) as Head)),
       html: getServerComponentHTML(_rendered.html),
       components: getClientIslandResponse(ssrContext),
       slots: getSlotIslandResponse(ssrContext),

pnpm-lock.yaml

@@ -62,6 +62,9 @@ importers:
       '@unhead/schema':
         specifier: 1.10.0
         version: 1.10.0
+      '@unhead/vue':
+        specifier: ^1.10.0
+        version: 1.10.0(vue@3.4.38(typescript@5.5.4))
       '@vitejs/plugin-vue':
         specifier: 5.1.2
         version: 5.1.2(vite@5.4.2(@types/node@20.16.1)(sass@1.69.4)(terser@5.27.0))(vue@3.4.38(typescript@5.5.4))
@@ -6785,9 +6788,6 @@ packages:
   uc.micro@2.1.0:
     resolution: {integrity: sha512-ARDJmphmdvUk6Glw7y9DQ2bFkKBHwQHLi2lsaH6PPmz/Ka9sFOBsBluozhDltWmnv9u/cF6Rt87znRTPV+yp/A==}
 
-  ufo@1.5.3:
-    resolution: {integrity: sha512-Y7HYmWaFwPUmkoQCUIAYpKqkOf+SbVj/2fJJZ4RJMCfZp0rTGwRbzQD+HghfnhKOjL9E01okqz+ncJskGYfBNw==}
-
   ufo@1.5.4:
     resolution: {integrity: sha512-UsUk3byDzKd04EyoZ7U4DOlxQaD14JUKQl6/P7wiX4FNvUfm3XL246n9W5AmqwW5RSFJ27NAuM0iLscAOYUiGQ==}
 
@@ -12617,7 +12617,7 @@ snapshots:
       serve-placeholder: 2.0.2
       serve-static: 1.15.0
       std-env: 3.7.0
-      ufo: 1.5.3
+      ufo: 1.5.4
       uncrypto: 0.1.3
       unctx: 2.3.1
       unenv: 1.10.0
@@ -14175,8 +14175,6 @@ snapshots:
 
   uc.micro@2.1.0: {}
 
-  ufo@1.5.3: {}
-
   ufo@1.5.4: {}
 
   uglify-js@3.17.4: {}

test/basic.test.ts

@@ -7,7 +7,8 @@ import { join, normalize } from 'pathe'
 import { $fetch as _$fetch, createPage, fetch, isDev, setup, startServer, url, useTestContext } from '@nuxt/test-utils/e2e'
 import { $fetchComponent } from '@nuxt/test-utils/experimental'
 
-import { expectNoClientErrors, expectWithPolling, gotoPath, isRenderingJson, parseData, parsePayload, renderPage } from './utils'
+import { resolveUnrefHeadInput } from '@unhead/vue'
+import { expectNoClientErrors, expectWithPolling, gotoPath, isRenderingJson, parseData, parsePayload, renderPage, resolveHead } from './utils'
 
 import type { NuxtIslandResponse } from '#app'
 
@@ -137,7 +138,7 @@ describe('pages', () => {
     // should apply attributes to client-only components
     expect(html).toContain('<div style="color:red;" class="client-only"></div>')
     // should render server-only components
-    expect(html.replace(/ data-island-uid="[^"]*"/, '')).toContain('<div class="server-only" style="background-color:gray;"> server-only component <div> server-only component child (non-server-only) </div></div>')
+    expect(html.replaceAll(/ data-island-uid="[^"]*"/g, '')).toContain('<div class="server-only" style="background-color:gray;"> server-only component <div> server-only component child (non-server-only) </div></div>')
     // should register global components automatically
     expect(html).toContain('global component registered automatically')
     expect(html).toContain('global component via suffix')
@@ -1929,6 +1930,12 @@ describe('server components/islands', () => {
     await page.close()
   })
 
+  it('/server-page', async () => {
+    const html = await $fetch<string>('/server-page')
+    // test island head
+    expect(html).toContain('<meta name="author" content="Nuxt">')
+  })
+
   it.skipIf(isDev)('should allow server-only components to set prerender hints', async () => {
     // @ts-expect-error ssssh! untyped secret property
     const publicDir = useTestContext().nuxt._nitro.options.output.publicDir
@@ -2138,15 +2145,15 @@ describe('component islands', () => {
 
     result.html = result.html.replace(/ data-island-uid="[^"]*"/g, '')
     if (isDev()) {
-      result.head.link = result.head.link.filter(l => !l.href!.includes('@nuxt+ui-templates') && (l.href!.startsWith('_nuxt/components/islands/') && l.href!.includes('_nuxt/components/islands/RouteComponent')))
+      result.head = resolveHead(result.head).map(h => ({
+        ...h,
+        link: h.link?.filter(l => typeof l.href !== 'string' || (!l.href.includes('_nuxt/components/islands/RouteComponent') && !l.href.includes('PureComponent') /* TODO: fix dev bug triggered by previous fetch of /islands */)),
+      })).filter(h => Object.values(h).some(h => !Array.isArray(h) || h.length))
     }
 
     expect(result).toMatchInlineSnapshot(`
       {
-        "head": {
+        "head": [],
-          "link": [],
-          "style": [],
-        },
         "html": "<pre data-island-uid>    Route: /foo
         </pre>",
       }
@@ -2160,15 +2167,15 @@ describe('component islands', () => {
       }),
     }))
     if (isDev()) {
-      result.head.link = result.head.link.filter(l => !l.href!.includes('@nuxt+ui-templates') && (l.href!.startsWith('_nuxt/components/islands/') && l.href!.includes('_nuxt/components/islands/LongAsyncComponent')))
+      result.head = resolveHead(result.head).map(h => ({
+        ...h,
+        link: h.link?.filter(l => typeof l.href !== 'string' || (!l.href.includes('_nuxt/components/islands/LongAsyncComponent') && !l.href.includes('PureComponent') /* TODO: fix dev bug triggered by previous fetch of /islands */)),
+      })).filter(h => Object.values(h).some(h => !Array.isArray(h) || h.length))
     }
     result.html = result.html.replaceAll(/ (data-island-uid|data-island-component)="([^"]*)"/g, '')
     expect(result).toMatchInlineSnapshot(`
       {
-        "head": {
+        "head": [],
-          "link": [],
-          "style": [],
-        },
         "html": "<div data-island-uid><div> count is above 2 </div><!--[--><div style="display: contents;" data-island-uid data-island-slot="default"><!--teleport start--><!--teleport end--></div><!--]--> that was very long ... <div id="long-async-component-count">3</div>  <!--[--><div style="display: contents;" data-island-uid data-island-slot="test"><!--teleport start--><!--teleport end--></div><!--]--><p>hello world !!!</p><!--[--><div style="display: contents;" data-island-uid data-island-slot="hello"><!--teleport start--><!--teleport end--></div><!--teleport start--><!--teleport end--><!--]--><!--[--><div style="display: contents;" data-island-uid data-island-slot="fallback"><!--teleport start--><!--teleport end--></div><!--teleport start--><!--teleport end--><!--]--></div>",
         "slots": {
           "default": {
@@ -2218,7 +2225,10 @@ describe('component islands', () => {
       }),
     }))
     if (isDev()) {
-      result.head.link = result.head.link.filter(l => !l.href!.includes('@nuxt+ui-templates') && (l.href!.startsWith('_nuxt/components/islands/') && l.href!.includes('_nuxt/components/islands/AsyncServerComponent')))
+      result.head = result.head.map(h => ({
+        ...h,
+        link: h.link?.filter(l => typeof l.href === 'string' && !l.href.includes('PureComponent') /* TODO: fix dev bug triggered by previous fetch of /islands */ && (!l.href.startsWith('_nuxt/components/islands/') || l.href.includes('AsyncServerComponent'))),
+      })).filter(h => Object.values(h).some(h => !Array.isArray(h) || h.length))
     }
     result.props = {}
     result.components = {}
@@ -2228,10 +2238,7 @@ describe('component islands', () => {
     expect(result).toMatchInlineSnapshot(`
       {
         "components": {},
-        "head": {
+        "head": [],
-          "link": [],
-          "style": [],
-        },
         "html": "<div data-island-uid> This is a .server (20ms) async component that was very long ... <div id="async-server-component-count">2</div><div class="sugar-counter"> Sugar Counter 12 x 1 = 12 <button> Inc </button></div><!--[--><div style="display: contents;" data-island-uid data-island-slot="default"><!--teleport start--><!--teleport end--></div><!--]--></div>",
         "props": {},
         "slots": {},
@@ -2243,7 +2250,10 @@ describe('component islands', () => {
     it('render server component with selective client hydration', async () => {
       const result = await $fetch<NuxtIslandResponse>('/__nuxt_island/ServerWithClient')
       if (isDev()) {
-        result.head.link = result.head.link.filter(l => !l.href!.includes('@nuxt+ui-templates') && (l.href!.startsWith('_nuxt/components/islands/') && l.href!.includes('_nuxt/components/islands/AsyncServerComponent')))
+        result.head = resolveHead(result.head).map(h => ({
+          ...h,
+          link: h.link?.filter(l => typeof l.href !== 'string' || (!l.href.includes('_nuxt/components/islands/LongAsyncComponent') && !l.href.includes('PureComponent') /* TODO: fix dev bug triggered by previous fetch of /islands */)),
+        })).filter(h => Object.values(h).some(h => !Array.isArray(h) || h.length))
       }
       const { components } = result
       result.components = {}
@@ -2255,10 +2265,7 @@ describe('component islands', () => {
       expect(result).toMatchInlineSnapshot(`
         {
           "components": {},
-          "head": {
+          "head": [],
-            "link": [],
-            "style": [],
-          },
           "html": "<div data-island-uid> ServerWithClient.server.vue : <p>count: 0</p> This component should not be preloaded <div><!--[--><div>a</div><div>b</div><div>c</div><!--]--></div> This is not interactive <div class="sugar-counter"> Sugar Counter 12 x 1 = 12 <button> Inc </button></div><div class="interactive-component-wrapper" style="border:solid 1px red;"> The component below is not a slot but declared as interactive <!--[--><div style="display: contents;" data-island-uid data-island-component="Counter"></div><!--teleport start--><!--teleport end--><!--]--></div></div>",
           "slots": {},
         }
@@ -2287,41 +2294,52 @@ describe('component islands', () => {
 
     if (isDev()) {
       const fixtureDir = normalize(fileURLToPath(new URL('./fixtures/basic', import.meta.url)))
-      for (const link of result.head.link) {
+      for (const head of result.head) {
-        link.href = link.href!.replace(fixtureDir, '/<rootDir>').replaceAll('//', '/')
+        for (const key in head) {
-        link.key = link.key!.replace(/-[a-z0-9]+$/i, '')
+          if (key === 'link') {
+            head[key] = head[key]?.map((h) => {
+              if (h.href) {
+                h.href = resolveUnrefHeadInput(h.href).replace(fixtureDir, '/<rootDir>').replaceAll('//', '/')
+              }
+              return h
+            })
+          }
+        }
       }
-      result.head.link.sort((a, b) => b.href!.localeCompare(a.href!))
     }
 
     // TODO: fix rendering of styles in webpack
     if (!isDev() && !isWebpack) {
       expect(normaliseIslandResult(result).head).toMatchInlineSnapshot(`
+        [
           {
-          "link": [],
             "style": [
               {
                 "innerHTML": "pre[data-v-xxxxx]{color:blue}",
-              "key": "island-style",
               },
             ],
-        }
+          },
+        ]
       `)
     } else if (isDev() && !isWebpack) {
       // TODO: resolve dev bug triggered by earlier fetch of /vueuse-head page
       // https://github.com/nuxt/nuxt/blob/main/packages/nuxt/src/core/runtime/nitro/renderer.ts#L139
-      result.head.link = result.head.link.filter(h => !h.href!.includes('SharedComponent'))
+      result.head = resolveHead(result.head).map(h => ({
+        ...h,
+        link: h.link?.filter(l => typeof l.href !== 'string' || !l.href.includes('SharedComponent')),
+      })).filter(h => Object.values(h).some(h => !Array.isArray(h) || h.length))
+
       expect(result.head).toMatchInlineSnapshot(`
+        [
           {
             "link": [
               {
                 "href": "/_nuxt/components/islands/PureComponent.vue?vue&type=style&index=0&scoped=c0c0cf89&lang.css",
-              "key": "island-link",
                 "rel": "stylesheet",
               },
             ],
-          "style": [],
+          },
-        }
+        ]
       `)
     }
 
@@ -2668,14 +2686,21 @@ describe('Node.js compatibility for client-side', () => {
 function normaliseIslandResult (result: NuxtIslandResponse) {
   return {
     ...result,
-    head: {
+    head: result.head.map((h) => {
-      ...result.head,
+      if (h.style) {
-      style: result.head.style.map(s => ({
+        for (const style of h.style) {
-        ...s,
+          if (typeof style !== 'string') {
-        innerHTML: (s.innerHTML || '').replace(/data-v-[a-z0-9]+/, 'data-v-xxxxx').replace(/\.[a-zA-Z0-9]+\.svg/, '.svg'),
+            if (style.innerHTML) {
-        key: s.key.replace(/-[a-z0-9]+$/i, ''),
+              style.innerHTML = (style.innerHTML as string).replace(/data-v-[a-z0-9]+/g, 'data-v-xxxxx')
-      })),
+            }
-    },
+            if (style.key) {
+              style.key = style.key.replace(/-[a-z0-9]+$/i, '')
+            }
+          }
+        }
+        return h
+      }
+    }),
   }
 }
 

test/bundle.test.ts

@@ -32,7 +32,7 @@ describe.skipIf(process.env.SKIP_BUNDLE_SIZE === 'true' || process.env.ECOSYSTEM
     const serverDir = join(rootDir, '.output/server')
 
     const serverStats = await analyzeSizes(['**/*.mjs', '!node_modules'], serverDir)
-    expect.soft(roundToKilobytes(serverStats.totalBytes)).toMatchInlineSnapshot(`"211k"`)
+    expect.soft(roundToKilobytes(serverStats.totalBytes)).toMatchInlineSnapshot(`"205k"`)
 
     const modules = await analyzeSizes('node_modules/**/*', serverDir)
     expect.soft(roundToKilobytes(modules.totalBytes)).toMatchInlineSnapshot(`"1355k"`)
@@ -73,7 +73,7 @@ describe.skipIf(process.env.SKIP_BUNDLE_SIZE === 'true' || process.env.ECOSYSTEM
     const serverDir = join(rootDir, '.output-inline/server')
 
     const serverStats = await analyzeSizes(['**/*.mjs', '!node_modules'], serverDir)
-    expect.soft(roundToKilobytes(serverStats.totalBytes)).toMatchInlineSnapshot(`"535k"`)
+    expect.soft(roundToKilobytes(serverStats.totalBytes)).toMatchInlineSnapshot(`"529k"`)
 
     const modules = await analyzeSizes('node_modules/**/*', serverDir)
     expect.soft(roundToKilobytes(modules.totalBytes)).toMatchInlineSnapshot(`"86.1k"`)

test/fixtures/basic/pages/index.vue

@@ -79,6 +79,11 @@
       style="color: red;"
       class="client-only"
     />
+    <NuxtIsland
+      ref="island"
+      name="AsyncServerComponent"
+      :props="{ count: 34 }"
+    />
     <ServerOnlyComponent
       class="server-only"
       style="background-color: gray;"
@@ -96,9 +101,10 @@
 import { setupDevtoolsPlugin } from '@vue/devtools-api'
 import { useRuntimeConfig } from '#imports'
 import { importedRE, importedValue } from '~/some-exports'
+import type { NuxtIsland, ServerOnlyComponent } from '#build/components'
 
 setupDevtoolsPlugin({}, () => {}) as any
-
+const island = ref<InstanceType<typeof ServerOnlyComponent>>()
 const config = useRuntimeConfig()
 
 const someValue = useState('val', () => 1)
@@ -107,7 +113,30 @@ const NestedCounter = resolveComponent('NestedCounter')
 if (!NestedCounter) {
   throw new Error('Component not found')
 }
-
+useHead({
+  meta: [
+    {
+      name: 'author',
+      content: 'Nuxt',
+      key: 'testkey',
+    },
+    {
+      name: 'author',
+      content: 'Nuxt',
+      key: 'testkey',
+    },
+  ],
+  script: [
+    {
+      innerHTML: 'console.log("my script")',
+      key: 'my-script',
+    },
+    {
+      innerHTML: 'console.log("my script")',
+      key: 'my-script',
+    },
+  ],
+}, { key: 'testkey' })
 definePageMeta({
   alias: '/some-alias',
   other: ref('test'),

test/fixtures/basic/pages/server-page.server.vue

@@ -8,3 +8,15 @@
     </NuxtLink>
   </div>
 </template>
+
+<script setup lang="ts">
+useHead({
+  title: 'Server Page',
+  meta: [
+    {
+      name: 'author',
+      content: 'Nuxt',
+    },
+  ],
+})
+</script>

test/utils.ts

@@ -5,6 +5,8 @@ import { parse } from 'devalue'
 import { reactive, ref, shallowReactive, shallowRef } from 'vue'
 import { createError } from 'h3'
 import { getBrowser, url, useTestContext } from '@nuxt/test-utils/e2e'
+import type { Head } from '@unhead/vue'
+import { resolveUnrefHeadInput } from '@unhead/vue'
 
 export const isRenderingJson = process.env.TEST_PAYLOAD !== 'js'
 
@@ -126,3 +128,7 @@ export function parseData (html: string) {
     attrs: _attrs,
   }
 }
+
+export function resolveHead (head: Head[]) {
+  return head.map(i => resolveUnrefHeadInput(i) as Head)
+}