fix(nuxt): remove div wrapper in client-only pages (#30425)

packages/nuxt/src/components/runtime/client-component.ts

@@ -1,32 +1,73 @@
-import { defineAsyncComponent, defineComponent, h } from 'vue'
-import type { AsyncComponentLoader } from 'vue'
-import ClientOnly from '#app/components/client-only'
+import { h, onMounted, ref } from 'vue'
+import type { AsyncComponentLoader, ComponentOptions } from 'vue'
+import { isPromise } from '@vue/shared'
 import { useNuxtApp } from '#app/nuxt'
+import ServerPlaceholder from '#app/components/server-placeholder'
 
 /* @__NO_SIDE_EFFECTS__ */
-export const createClientPage = (loader: AsyncComponentLoader) => {
-  const page = defineAsyncComponent(import.meta.dev
-    ? () => loader().then((m) => {
+export async function createClientPage (loader: AsyncComponentLoader) {
+  // vue-router: Write "() => import('./MyPage.vue')" instead of "defineAsyncComponent(() => import('./MyPage.vue'))".
+  const m = await loader()
+  const c = m.default || m
+  if (import.meta.dev) {
     // mark component as client-only for `definePageMeta`
-        (m.default || m).__clientOnlyPage = true
-        return m.default || m
-      })
-    : loader)
+    c.__clientOnlyPage = true
+  }
+  return pageToClientOnly(c)
+}
 
-  return defineComponent({
-    inheritAttrs: false,
-    setup (_, { attrs }) {
+const cache = new WeakMap()
+
+function pageToClientOnly<T extends ComponentOptions> (component: T) {
+  if (import.meta.server) {
+    return ServerPlaceholder
+  }
+
+  if (cache.has(component)) {
+    return cache.get(component)
+  }
+
+  const clone = { ...component }
+
+  if (clone.render) {
+    // override the component render (non script setup component) or dev mode
+    clone.render = (ctx: any, cache: any, $props: any, $setup: any, $data: any, $options: any) => ($setup.mounted$ ?? ctx.mounted$)
+      ? h(component.render?.bind(ctx)(ctx, cache, $props, $setup, $data, $options))
+      : h('div')
+  } else if (clone.template) {
+    // handle runtime-compiler template
+    clone.template = `
+      <template v-if="mounted$">${component.template}</template>
+      <template v-else><div></div></template>
+    `
+  }
+
+  clone.setup = (props, ctx) => {
     const nuxtApp = useNuxtApp()
-      if (import.meta.server || nuxtApp.isHydrating) {
-        // wrapped with div to avoid Transition issues
-        // @see https://github.com/nuxt/nuxt/pull/25037#issuecomment-1877423894
-        return () => h('div', [
-          h(ClientOnly, undefined, {
-            default: () => h(page, attrs),
-          }),
-        ])
-      }
-      return () => h(page, attrs)
-    },
+    const mounted$ = ref(nuxtApp.isHydrating === false)
+    onMounted(() => {
+      mounted$.value = true
     })
+    const setupState = component.setup?.(props, ctx) || {}
+    if (isPromise(setupState)) {
+      return Promise.resolve(setupState).then((setupState: any) => {
+        if (typeof setupState !== 'function') {
+          setupState = setupState || {}
+          setupState.mounted$ = mounted$
+          return setupState
+        }
+        return (...args: any[]) => (mounted$.value || !nuxtApp.isHydrating) ? h(setupState(...args)) : h('div')
+      })
+    } else {
+      return typeof setupState === 'function'
+        ? (...args: any[]) => (mounted$.value || !nuxtApp.isHydrating)
+            ? h(setupState(...args))
+            : h('div')
+        : Object.assign(setupState, { mounted$ })
+    }
+  }
+
+  cache.set(component, clone)
+
+  return clone
 }

test/bundle.test.ts

@@ -38,7 +38,7 @@ describe.skipIf(process.env.SKIP_BUNDLE_SIZE === 'true' || process.env.ECOSYSTEM
   it('default client bundle size (pages)', async () => {
     const clientStats = await analyzeSizes(['**/*.js'], join(pagesRootDir, '.output/public'))
 
-    expect.soft(roundToKilobytes(clientStats!.totalBytes)).toMatchInlineSnapshot(`"175k"`)
+    expect.soft(roundToKilobytes(clientStats!.totalBytes)).toMatchInlineSnapshot(`"176k"`)
 
     const files = clientStats!.files.map(f => f.replace(/\..*\.js/, '.js'))
 
@@ -127,7 +127,7 @@ describe.skipIf(process.env.SKIP_BUNDLE_SIZE === 'true' || process.env.ECOSYSTEM
     const serverDir = join(pagesRootDir, '.output/server')
 
     const serverStats = await analyzeSizes(['**/*.mjs', '!node_modules'], serverDir)
-    expect.soft(roundToKilobytes(serverStats.totalBytes)).toMatchInlineSnapshot(`"301k"`)
+    expect.soft(roundToKilobytes(serverStats.totalBytes)).toMatchInlineSnapshot(`"300k"`)
 
     const modules = await analyzeSizes(['node_modules/**/*'], serverDir)
     expect.soft(roundToKilobytes(modules.totalBytes)).toMatchInlineSnapshot(`"1402k"`)

test/nuxt/client-only.test.ts

@@ -0,0 +1,90 @@
+import { describe, expect, it } from 'vitest'
+import type { ComponentOptions } from 'vue'
+import { Suspense, defineComponent, h, toDisplayString, useAttrs } from 'vue'
+import { mountSuspended } from '@nuxt/test-utils/runtime'
+import { flushPromises, mount } from '@vue/test-utils'
+
+import { createClientOnly } from '../../packages/nuxt/src/app/components/client-only'
+import { createClientPage } from '../../packages/nuxt/dist/components/runtime/client-component'
+
+describe('client pages', () => {
+  it('should render without a wrapper', async () => {
+    const { resolve, wrapper } = createWrappedClientPage()
+    expect(wrapper.html()).toMatchInlineSnapshot(`
+      "<div>
+        <div id="fallback">loading</div>
+      </div>"
+    `)
+    resolve()
+    await flushPromises()
+    expect(wrapper.html()).toMatchInlineSnapshot(`
+      "<div>
+        <div id="async">async resolved</div>
+      </div>"
+    `)
+  })
+
+  it('createClient should retrieve attributes with useAttrs()', async () => {
+    const wrapper = await mountSuspended(createClientOnly(Client as ComponentOptions), {
+      attrs: {
+        id: 'client',
+      },
+    })
+
+    expect(wrapper.html()).toMatchInlineSnapshot(`
+      "<div id="client">{
+        "id": "client"
+        }</div>"
+    `)
+  })
+
+  it('should be suspensed when out of hydration', async () => {
+    const { resolve, wrapper } = createWrappedClientPage()
+
+    await flushPromises()
+    expect(wrapper.find('#fallback').exists()).toBe(true)
+    expect(wrapper.find('#async').exists()).toBe(false)
+
+    resolve!()
+    await flushPromises()
+    expect(wrapper.find('#async').exists()).toBe(true)
+    expect(wrapper.find('#fallback').exists()).toBe(false)
+  })
+})
+
+const Client = defineComponent({
+  name: 'TestClient',
+  setup () {
+    const attrs = useAttrs()
+    return () => h('div', {}, toDisplayString(attrs))
+  },
+})
+
+function createWrappedClientPage () {
+  let resolve: () => void
+  const promise = new Promise<void>((_resolve) => {
+    resolve = _resolve
+  })
+
+  const comp = defineComponent({
+    async setup () {
+      await promise
+      return () => h('div', { id: 'async' }, 'async resolved')
+    },
+  })
+
+  const ClientPage = defineAsyncComponent(() => createClientPage(() => Promise.resolve(comp)))
+
+  const wrapper = mount({
+    setup () {
+      return () => h('div', {}, [
+        h(Suspense, {}, {
+          default: () => h(ClientPage, {}),
+          fallback: () => h('div', { id: 'fallback' }, 'loading'),
+        }),
+      ])
+    },
+  })
+
+  return { resolve: resolve!, wrapper }
+}

test/nuxt/client.test.ts

@@ -1,67 +0,0 @@
-import { describe, expect, it } from 'vitest'
-import type { ComponentOptions } from 'vue'
-import { Suspense, defineComponent, h, toDisplayString, useAttrs } from 'vue'
-import { mountSuspended } from '@nuxt/test-utils/runtime'
-import { flushPromises, mount } from '@vue/test-utils'
-import { createClientOnly } from '../../packages/nuxt/src/app/components/client-only'
-import { createClientPage } from '../../packages/nuxt/dist/components/runtime/client-component'
-
-const Client = defineComponent({
-  name: 'TestClient',
-  setup () {
-    const attrs = useAttrs()
-    return () => h('div', {}, toDisplayString(attrs))
-  },
-})
-
-describe('createClient attribute inheritance', () => {
-  it('should retrieve attributes with useAttrs()', async () => {
-    const wrapper = await mountSuspended(createClientOnly(Client as ComponentOptions), {
-      attrs: {
-        id: 'client',
-      },
-    })
-
-    expect(wrapper.html()).toMatchInlineSnapshot(`
-      "<div id="client">{
-        "id": "client"
-        }</div>"
-    `)
-  })
-})
-
-describe('client page', () => {
-  it('Should be suspensed when out of hydration', async () => {
-    let resolve
-    const promise = new Promise((_resolve) => {
-      resolve = _resolve
-    })
-
-    const comp = defineComponent({
-      async setup () {
-        await promise
-        return () => h('div', { id: 'async' }, 'async resolved')
-      },
-    })
-
-    const wrapper = mount({
-      setup () {
-        return () => h('div', {}, [
-          h(Suspense, {}, {
-            default: () => h(createClientPage(() => Promise.resolve(comp)), {}),
-            fallback: () => h('div', { id: 'fallback' }, 'loading'),
-          }),
-        ])
-      },
-    })
-
-    await flushPromises()
-    expect(wrapper.find('#fallback').exists()).toBe(true)
-    expect(wrapper.find('#async').exists()).toBe(false)
-
-    resolve!()
-    await flushPromises()
-    expect(wrapper.find('#async').exists()).toBe(true)
-    expect(wrapper.find('#fallback').exists()).toBe(false)
-  })
-})