feat(nuxt): normalise component names to match nuxt pattern (#28745)

docs/1.getting-started/12.upgrade.md

@@ -73,6 +73,7 @@ export default defineNuxtConfig({
   //   resetAsyncDataToUndefined: true,
   //   templateUtils: true,
   //   relativeWatchPaths: true,
+  //   normalizeComponentNames: false
   //   defaults: {
   //     useAsyncData: {
   //       deep: true
@@ -223,6 +224,43 @@ The migration should be straightforward:
 + console.log(route.name)
 ```
 
+#### Normalized Component Names
+
+🚦 **Impact Level**: Moderate
+
+Vue will now generate component names that match the Nuxt pattern for component naming.
+
+##### What Changed
+
+By default, if you haven't set it manually, Vue will assign a component name that matches
+the filename of the component.
+
+```bash [Directory structure]
+├─ components/
+├─── SomeFolder/
+├───── MyComponent.vue
+```
+
+In this case, the component name would be `MyComponent`, as far as Vue is concerned. If you wanted to use `<KeepAlive>` with it, or identify it in the Vue DevTools, you would need to use this name.
+
+But in order to auto-import it, you would need to use `SomeFolderMyComponent`.
+
+With this change, these two values will match, and Vue will generate a component name that matches the Nuxt pattern for component naming.
+
+##### Migration Steps
+
+Ensure that you use the updated name in any tests which use `findComponent` from `@vue/test-utils` and in any `<KeepAlive>` which depends on the name of your component.
+
+Alternatively, for now, you can disable this behaviour with:
+
+```ts twoslash [nuxt.config.ts]
+export default defineNuxtConfig({
+  experimental: {
+    normalizeComponentNames: false
+  }
+})
+```
+
 #### Shared Prerender Data
 
 🚦 **Impact Level**: Medium

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

@@ -442,3 +442,31 @@ In addition, any changes to files within `srcDir` will trigger a rebuild of the
 ::note
 A maximum of 10 cache tarballs are kept.
 ::
+
+## normalizeComponentNames
+
+Ensure that auto-generated Vue component names match the full component name
+you would use to auto-import the component.
+
+```ts twoslash [nuxt.config.ts]
+export default defineNuxtConfig({
+  experimental: {
+    normalizeComponentNames: true
+  }
+})
+```
+
+By default, if you haven't set it manually, Vue will assign a component name that matches
+the filename of the component.
+
+```bash [Directory structure]
+├─ components/
+├─── SomeFolder/
+├───── MyComponent.vue
+```
+
+In this case, the component name would be `MyComponent`, as far as Vue is concerned. If you wanted to use `<KeepAlive>` with it, or identify it in the Vue DevTools, you would need to use this component.
+
+But in order to auto-import it, you would need to use `SomeFolderMyComponent`.
+
+By setting `experimental.normalizeComponentNames`, these two values match, and Vue will generate a component name that matches the Nuxt pattern for component naming.

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

@@ -61,9 +61,12 @@ export default defineNuxtConfig({
     app: 'app'
   },
   experimental: {
+    sharedPrerenderData: false,
     compileTemplate: true,
+    resetAsyncDataToUndefined: true,
     templateUtils: true,
     relativeWatchPaths: true,
+    normalizeComponentNames: false
     defaults: {
       useAsyncData: {
         deep: true

packages/nuxt/src/components/module.ts

@@ -1,16 +1,18 @@
 import { existsSync, statSync, writeFileSync } from 'node:fs'
 import { isAbsolute, join, normalize, relative, resolve } from 'pathe'
-import { addPluginTemplate, addTemplate, addTypeTemplate, addVitePlugin, addWebpackPlugin, defineNuxtModule, logger, resolveAlias, resolvePath, updateTemplates } from '@nuxt/kit'
+import { addBuildPlugin, addPluginTemplate, addTemplate, addTypeTemplate, addVitePlugin, addWebpackPlugin, defineNuxtModule, logger, resolveAlias, resolvePath, updateTemplates } from '@nuxt/kit'
 import type { Component, ComponentsDir, ComponentsOptions } from 'nuxt/schema'
 
 import { distDir } from '../dirs'
-import { clientFallbackAutoIdPlugin } from './client-fallback-auto-id'
 import { componentNamesTemplate, componentsIslandsTemplate, componentsMetadataTemplate, componentsPluginTemplate, componentsTypeTemplate } from './templates'
 import { scanComponents } from './scan'
-import { loaderPlugin } from './loader'
-import { TreeShakeTemplatePlugin } from './tree-shake'
-import { componentsChunkPlugin, islandsTransform } from './islandsTransform'
-import { createTransformPlugin } from './transform'
+
+import { ClientFallbackAutoIdPlugin } from './plugins/client-fallback-auto-id'
+import { LoaderPlugin } from './plugins/loader'
+import { componentsChunkPlugin, islandsTransform } from './plugins/islands-transform'
+import { createTransformPlugin } from './plugins/transform'
+import { TreeShakeTemplatePlugin } from './plugins/tree-shake'
+import { ComponentNamePlugin } from './plugins/component-names'
 
 const isPureObjectOrString = (val: any) => (!Array.isArray(val) && typeof val === 'object') || typeof val === 'string'
 const isDirectory = (p: string) => { try { return statSync(p).isDirectory() } catch { return false } }
@@ -42,6 +44,11 @@ export default defineNuxtModule<ComponentsOptions>({
         : context.components
     }
 
+    if (nuxt.options.experimental.normalizeComponentNames) {
+      addBuildPlugin(ComponentNamePlugin({ sourcemap: !!nuxt.options.sourcemap.client, getComponents }), { server: false })
+      addBuildPlugin(ComponentNamePlugin({ sourcemap: !!nuxt.options.sourcemap.server, getComponents }), { client: false })
+    }
+
     const normalizeDirs = (dir: any, cwd: string, options?: { priority?: number }): ComponentsDir[] => {
       if (Array.isArray(dir)) {
         return dir.map(dir => normalizeDirs(dir, cwd, options)).flat().sort(compareDirByPathLength)
@@ -127,14 +134,14 @@ export default defineNuxtModule<ComponentsOptions>({
       addTemplate(componentsMetadataTemplate)
     }
 
-    const unpluginServer = createTransformPlugin(nuxt, getComponents, 'server')
-    const unpluginClient = createTransformPlugin(nuxt, getComponents, 'client')
+    const TransformPluginServer = createTransformPlugin(nuxt, getComponents, 'server')
+    const TransformPluginClient = createTransformPlugin(nuxt, getComponents, 'client')
 
-    addVitePlugin(() => unpluginServer.vite(), { server: true, client: false })
-    addVitePlugin(() => unpluginClient.vite(), { server: false, client: true })
+    addVitePlugin(() => TransformPluginServer.vite(), { server: true, client: false })
+    addVitePlugin(() => TransformPluginClient.vite(), { server: false, client: true })
 
-    addWebpackPlugin(() => unpluginServer.webpack(), { server: true, client: false })
-    addWebpackPlugin(() => unpluginClient.webpack(), { server: false, client: true })
+    addWebpackPlugin(() => TransformPluginServer.webpack(), { server: true, client: false })
+    addWebpackPlugin(() => TransformPluginClient.webpack(), { server: false, client: true })
 
     // Do not prefetch global components chunks
     nuxt.hook('build:manifest', (manifest) => {
@@ -223,12 +230,12 @@ export default defineNuxtModule<ComponentsOptions>({
         }))
       }
       if (nuxt.options.experimental.clientFallback) {
-        config.plugins.push(clientFallbackAutoIdPlugin.vite({
+        config.plugins.push(ClientFallbackAutoIdPlugin.vite({
           sourcemap: !!nuxt.options.sourcemap[mode],
           rootDir: nuxt.options.rootDir,
         }))
       }
-      config.plugins.push(loaderPlugin.vite({
+      config.plugins.push(LoaderPlugin.vite({
         sourcemap: !!nuxt.options.sourcemap[mode],
         getComponents,
         mode,
@@ -292,12 +299,12 @@ export default defineNuxtModule<ComponentsOptions>({
           }))
         }
         if (nuxt.options.experimental.clientFallback) {
-          config.plugins.push(clientFallbackAutoIdPlugin.webpack({
+          config.plugins.push(ClientFallbackAutoIdPlugin.webpack({
             sourcemap: !!nuxt.options.sourcemap[mode],
             rootDir: nuxt.options.rootDir,
           }))
         }
-        config.plugins.push(loaderPlugin.webpack({
+        config.plugins.push(LoaderPlugin.webpack({
           sourcemap: !!nuxt.options.sourcemap[mode],
           getComponents,
           mode,

packages/nuxt/src/components/plugins/client-fallback-auto-id.ts

@@ -3,7 +3,7 @@ import type { ComponentsOptions } from '@nuxt/schema'
 import MagicString from 'magic-string'
 import { isAbsolute, relative } from 'pathe'
 import { hash } from 'ohash'
-import { isVue } from '../core/utils'
+import { isVue } from '../../core/utils'
 
 interface LoaderOptions {
   sourcemap?: boolean
@@ -12,7 +12,7 @@ interface LoaderOptions {
 }
 const CLIENT_FALLBACK_RE = /<(?:NuxtClientFallback|nuxt-client-fallback)(?: [^>]*)?>/
 const CLIENT_FALLBACK_GLOBAL_RE = /<(NuxtClientFallback|nuxt-client-fallback)( [^>]*)?>/g
-export const clientFallbackAutoIdPlugin = createUnplugin((options: LoaderOptions) => {
+export const ClientFallbackAutoIdPlugin = createUnplugin((options: LoaderOptions) => {
   const exclude = options.transform?.exclude || []
   const include = options.transform?.include || []
 

packages/nuxt/src/components/plugins/component-names.ts

@@ -0,0 +1,46 @@
+import { createUnplugin } from 'unplugin'
+import MagicString from 'magic-string'
+import type { Component } from 'nuxt/schema'
+import { isVue } from '../../core/utils'
+
+interface NameDevPluginOptions {
+  sourcemap: boolean
+  getComponents: () => Component[]
+}
+/**
+ * Set the default name of components to their PascalCase name
+ */
+export const ComponentNamePlugin = (options: NameDevPluginOptions) => createUnplugin(() => {
+  return {
+    name: 'nuxt:component-name-plugin',
+    enforce: 'post',
+    transformInclude (id) {
+      return isVue(id) || !!id.match(/\.[tj]sx$/)
+    },
+    transform (code, id) {
+      const filename = id.match(/([^/\\]+)\.\w+$/)?.[1]
+      if (!filename) {
+        return
+      }
+
+      const component = options.getComponents().find(c => c.filePath === id)
+
+      if (!component) {
+        return
+      }
+
+      const NAME_RE = new RegExp(`__name:\\s*['"]${filename}['"]`)
+      const s = new MagicString(code)
+      s.replace(NAME_RE, `__name: ${JSON.stringify(component.pascalName)}`)
+
+      if (s.hasChanged()) {
+        return {
+          code: s.toString(),
+          map: options.sourcemap
+            ? s.generateMap({ hires: true })
+            : undefined,
+        }
+      }
+    },
+  }
+})

packages/nuxt/src/components/plugins/islands-transform.ts

@@ -9,7 +9,7 @@ import { ELEMENT_NODE, parse, walk } from 'ultrahtml'
 import { hash } from 'ohash'
 import { resolvePath } from '@nuxt/kit'
 import defu from 'defu'
-import { isVue } from '../core/utils'
+import { isVue } from '../../core/utils'
 
 interface ServerOnlyComponentTransformPluginOptions {
   getComponents: () => Component[]

packages/nuxt/src/components/plugins/loader.ts

@@ -6,8 +6,8 @@ import { resolve } from 'pathe'
 import type { Component, ComponentsOptions } from 'nuxt/schema'
 
 import { logger, tryUseNuxt } from '@nuxt/kit'
-import { distDir } from '../dirs'
-import { isVue } from '../core/utils'
+import { distDir } from '../../dirs'
+import { isVue } from '../../core/utils'
 
 interface LoaderOptions {
   getComponents (): Component[]
@@ -17,7 +17,7 @@ interface LoaderOptions {
   experimentalComponentIslands?: boolean
 }
 
-export const loaderPlugin = createUnplugin((options: LoaderOptions) => {
+export const LoaderPlugin = createUnplugin((options: LoaderOptions) => {
   const exclude = options.transform?.exclude || []
   const include = options.transform?.include || []
   const serverComponentRuntime = resolve(distDir, 'components/runtime/server-component')
@@ -49,7 +49,7 @@ export const loaderPlugin = createUnplugin((options: LoaderOptions) => {
           // @ts-expect-error TODO: refactor to nuxi
           if (component._internal_install && tryUseNuxt()?.options.test === false) {
             // @ts-expect-error TODO: refactor to nuxi
-            import('../core/features').then(({ installNuxtModule }) => installNuxtModule(component._internal_install))
+            import('../../core/features').then(({ installNuxtModule }) => installNuxtModule(component._internal_install))
           }
           let identifier = map.get(component) || `__nuxt_component_${num++}`
           map.set(component, identifier)

packages/nuxt/src/components/plugins/transform.ts

@@ -7,8 +7,8 @@ import { parseURL } from 'ufo'
 import { parseQuery } from 'vue-router'
 import { normalize, resolve } from 'pathe'
 import { genImport } from 'knitwork'
-import { distDir } from '../dirs'
-import type { getComponentsT } from './module'
+import { distDir } from '../../dirs'
+import type { getComponentsT } from '../module'
 
 const COMPONENT_QUERY_RE = /[?&]nuxt_component=/
 

packages/nuxt/src/components/plugins/tree-shake.ts

@@ -6,7 +6,7 @@ import type { AssignmentProperty, CallExpression, Identifier, Literal, MemberExp
 import { createUnplugin } from 'unplugin'
 import type { Component } from '@nuxt/schema'
 import { resolve } from 'pathe'
-import { distDir } from '../dirs'
+import { distDir } from '../../dirs'
 
 interface TreeShakeTemplatePluginOptions {
   sourcemap?: boolean

packages/nuxt/test/components-transform.test.ts

@@ -4,7 +4,7 @@ import type { Component, Nuxt } from '@nuxt/schema'
 import { kebabCase } from 'scule'
 import { normalize } from 'pathe'
 
-import { createTransformPlugin } from '../src/components/transform'
+import { createTransformPlugin } from '../src/components/plugins/transform'
 
 describe('components:transform', () => {
   it('should transform #components imports', async () => {

packages/nuxt/test/islandTransform.test.ts

@@ -2,7 +2,7 @@ import { describe, expect, it, vi } from 'vitest'
 import type { Plugin } from 'vite'
 import type { Component } from '@nuxt/schema'
 import type { UnpluginOptions } from 'unplugin'
-import { islandsTransform } from '../src/components/islandsTransform'
+import { islandsTransform } from '../src/components/plugins/islands-transform'
 import { normalizeLineEndings } from './utils'
 
 const getComponents = () => [{

packages/nuxt/test/treeshake-client.test.ts

@@ -6,7 +6,7 @@ import type { Plugin } from 'vite'
 import { Parser } from 'acorn'
 import type { Options } from '@vitejs/plugin-vue'
 import _vuePlugin from '@vitejs/plugin-vue'
-import { TreeShakeTemplatePlugin } from '../src/components/tree-shake'
+import { TreeShakeTemplatePlugin } from '../src/components/plugins/tree-shake'
 import { fixtureDir, normalizeLineEndings } from './utils'
 
 // mock due to differences of results between windows and linux

packages/schema/src/config/experimental.ts

@@ -544,5 +544,15 @@ export default defineUntypedSchema({
      * This only works for source files within `srcDir` and `serverDir` for the Vue/Nitro parts of your app.
      */
     buildCache: false,
+
+    /**
+     * Ensure that auto-generated Vue component names match the full component name
+     * you would use to auto-import the component.
+     */
+    normalizeComponentNames: {
+      $resolve: async (val, get) => {
+        return val ?? ((await get('future') as Record<string, unknown>).compatibilityVersion === 4)
+      },
+    },
   },
 })