fix(nuxt)!: remove old experimental options (#27749)

docs/2.guide/3.going-further/1.experimental-features.md

@@ -57,20 +57,6 @@ export default defineNuxtConfig({
 This feature will likely be removed in a near future.
 ::
 
-## treeshakeClientOnly
-
-Tree shakes contents of client-only components from server bundle.
-
-*Enabled by default.*
-
-```ts twoslash [nuxt.config.ts]
-export default defineNuxtConfig({
-  experimental: {
-    treeshakeClientOnly: true
-  }
-})
-```
-
 ## emitRouteChunkError
 
 Emits `app:chunkError` hook when there is an error loading vite/webpack chunks. Default behavior is to perform a hard reload of the new route when a chunk fails to load.
@@ -238,44 +224,6 @@ export default defineNuxtConfig({
 You can follow the server components roadmap on GitHub.
 ::
 
-## configSchema
-
-Enables config schema support.
-
-*Enabled by default.*
-
-```ts twoslash [nuxt.config.ts]
-export default defineNuxtConfig({
-  experimental: {
-    configSchema: true
-  }
-})
-```
-
-## polyfillVueUseHead
-
-Adds a compatibility layer for modules, plugins, or user code relying on the old `@vueuse/head` API.
-
-```ts twoslash [nuxt.config.ts]
-export default defineNuxtConfig({
-  experimental: {
-    polyfillVueUseHead: false
-  }
-})
-```
-
-## respectNoSSRHeader
-
-Allow disabling Nuxt SSR responses by setting the `x-nuxt-no-ssr` header.
-
-```ts twoslash [nuxt.config.ts]
-export default defineNuxtConfig({
-  experimental: {
-    respectNoSSRHeader: false
-  }
-})
-```
-
 ## localLayerAliases
 
 Resolve `~`, `~~`, `@` and `@@` aliases located within layers with respect to their layer source and root directories.

packages/nuxt/src/components/module.ts

@@ -216,7 +216,7 @@ export default defineNuxtModule<ComponentsOptions>({
       const mode = isClient ? 'client' : 'server'
 
       config.plugins = config.plugins || []
-      if (nuxt.options.experimental.treeshakeClientOnly && isServer) {
+      if (isServer) {
         config.plugins.push(TreeShakeTemplatePlugin.vite({
           sourcemap: !!nuxt.options.sourcemap[mode],
           getComponents,
@@ -285,7 +285,7 @@ export default defineNuxtModule<ComponentsOptions>({
       configs.forEach((config) => {
         const mode = config.name === 'client' ? 'client' : 'server'
         config.plugins = config.plugins || []
-        if (nuxt.options.experimental.treeshakeClientOnly && mode === 'server') {
+        if (mode === 'server') {
           config.plugins.push(TreeShakeTemplatePlugin.webpack({
             sourcemap: !!nuxt.options.sourcemap[mode],
             getComponents,

packages/nuxt/src/core/nitro.ts

@@ -343,15 +343,6 @@ export async function initNitro (nuxt: Nuxt & { _nitro?: Nitro }) {
     }
   }
 
-  // Add backward-compatible middleware to respect `x-nuxt-no-ssr` header
-  if (nuxt.options.experimental.respectNoSSRHeader) {
-    nitroConfig.handlers = nitroConfig.handlers || []
-    nitroConfig.handlers.push({
-      handler: resolve(distDir, 'core/runtime/nitro/no-ssr'),
-      middleware: true,
-    })
-  }
-
   // Register nuxt protection patterns
   nitroConfig.rollupConfig!.plugins = await nitroConfig.rollupConfig!.plugins || []
   nitroConfig.rollupConfig!.plugins = toArray(nitroConfig.rollupConfig!.plugins)

packages/nuxt/src/core/schema.ts

@@ -20,9 +20,6 @@ export default defineNuxtModule({
     name: 'nuxt-config-schema',
   },
   async setup (_, nuxt) {
-    if (!nuxt.options.experimental.configSchema) {
-      return
-    }
     const resolver = createResolver(import.meta.url)
 
     // Initialize untyped/jiti loader

packages/nuxt/src/head/module.ts

@@ -52,11 +52,6 @@ export default defineNuxtModule<NuxtOptions['unhead']>({
 
     // Opt-out feature allowing dependencies using @vueuse/head to work
     const unheadVue = await tryResolveModule('@unhead/vue', nuxt.options.modulesDir) || '@unhead/vue'
-    if (nuxt.options.experimental.polyfillVueUseHead) {
-      // backwards compatibility
-      nuxt.options.alias['@vueuse/head'] = unheadVue
-      addPlugin({ src: resolve(runtimeDir, 'plugins/vueuse-head-polyfill') })
-    }
 
     addTemplate({
       filename: 'unhead-plugins.mjs',

packages/nuxt/src/head/runtime/plugins/vueuse-head-polyfill.ts

@@ -1,10 +0,0 @@
-import { polyfillAsVueUseHead } from '@unhead/vue/polyfill'
-import { defineNuxtPlugin } from '#app/nuxt'
-
-export default defineNuxtPlugin({
-  name: 'nuxt:vueuse-head-polyfill',
-  setup (nuxtApp) {
-    // avoid breaking ecosystem dependencies using low-level @vueuse/head APIs
-    polyfillAsVueUseHead(nuxtApp.vueApp._context.provides.usehead)
-  },
-})

packages/schema/src/config/experimental.ts

@@ -106,22 +106,6 @@ export default defineUntypedSchema({
      */
     externalVue: true,
 
-    /**
-     * Tree shakes contents of client-only components from server bundle.
-     * @see [Nuxt PR #5750](https://github.com/nuxt/framework/pull/5750)
-     * @deprecated This option will no longer be configurable in Nuxt v4
-     */
-    treeshakeClientOnly: {
-      async $resolve (val, get) {
-        const isV4 = ((await get('future') as Record<string, unknown>).compatibilityVersion === 4)
-        if (isV4 && val === false) {
-          console.warn('Enabling `experimental.treeshakeClientOnly` in v4 compatibility mode as it will no longer be configurable in Nuxt v4.')
-          return true
-        }
-        return val ?? true
-      },
-    },
-
     /**
      * Emit `app:chunkError` hook when there is an error loading vite/webpack
      * chunks.
@@ -226,55 +210,6 @@ export default defineUntypedSchema({
       },
     },
 
-    /**
-     * Config schema support
-     * @see [Nuxt Issue #15592](https://github.com/nuxt/nuxt/issues/15592)
-     * @deprecated This option will no longer be configurable in Nuxt v4
-     */
-    configSchema: {
-      async $resolve (val, get) {
-        const isV4 = ((await get('future') as Record<string, unknown>).compatibilityVersion === 4)
-        if (isV4 && val === false) {
-          console.warn('Enabling `experimental.configSchema` in v4 compatibility mode as it will no longer be configurable in Nuxt v4.')
-          return true
-        }
-        return val ?? true
-      },
-    },
-
-    /**
-     * Whether or not to add a compatibility layer for modules, plugins or user code relying on the old
-     * `@vueuse/head` API.
-     *
-     * This is disabled to reduce the client-side bundle by ~0.5kb.
-     * @deprecated This feature will be removed in Nuxt v4.
-     */
-    polyfillVueUseHead: {
-      async $resolve (val, get) {
-        const isV4 = ((await get('future') as Record<string, unknown>).compatibilityVersion === 4)
-        if (isV4 && val === true) {
-          console.warn('Disabling `experimental.polyfillVueUseHead` in v4 compatibility mode as it will no longer be configurable in Nuxt v4.')
-          return false
-        }
-        return val ?? false
-      },
-    },
-
-    /**
-     * Allow disabling Nuxt SSR responses by setting the `x-nuxt-no-ssr` header.
-     * @deprecated This feature will be removed in Nuxt v4.
-     */
-    respectNoSSRHeader: {
-      async $resolve (val, get) {
-        const isV4 = ((await get('future') as Record<string, unknown>).compatibilityVersion === 4)
-        if (isV4 && val === true) {
-          console.warn('Disabling `experimental.respectNoSSRHeader` in v4 compatibility mode as it will no longer be configurable in Nuxt v4.')
-          return false
-        }
-        return val ?? false
-      },
-    },
-
     /** Resolve `~`, `~~`, `@` and `@@` aliases located within layers with respect to their layer source and root directories. */
     localLayerAliases: true,