fix(vite): extract styles for shared chunks (#25455)

packages/vite/src/plugins/ssr-styles.ts

@@ -8,7 +8,7 @@ import type { Component } from '@nuxt/schema'
 import MagicString from 'magic-string'
 import { findStaticImports } from 'mlly'
 
-import { isCSS } from '../utils'
+import { isCSS, isVue } from '../utils'
 
 interface SSRStylePluginOptions {
   srcDir: string
@@ -107,25 +107,31 @@ export function ssrStylesPlugin (options: SSRStylePluginOptions): Plugin {
       })
     },
     renderChunk (_code, chunk) {
-      if (!chunk.facadeModuleId) { return null }
-
+      const isEntry = chunk.facadeModuleId === options.entry
+      if (isEntry) {
+        options.clientCSSMap[chunk.facadeModuleId!] ||= new Set()
+      }
+      for (const moduleId of [chunk.facadeModuleId, ...chunk.moduleIds].filter(Boolean) as string[]) {
         // 'Teleport' CSS chunks that made it into the bundle on the client side
         // to be inlined on server rendering
         if (options.mode === 'client') {
-        options.clientCSSMap[chunk.facadeModuleId] ||= new Set()
-        for (const id of chunk.moduleIds) {
-          if (isCSS(id)) {
-            options.clientCSSMap[chunk.facadeModuleId].add(id)
+          options.clientCSSMap[moduleId] ||= new Set()
+          if (isCSS(moduleId)) {
+            // Vue files can (also) be their own entrypoints as they are tracked separately
+            if (isVue(moduleId)) {
+              options.clientCSSMap[moduleId].add(moduleId)
+            }
+            // This is required to track CSS in entry chunk
+            if (isEntry) {
+              options.clientCSSMap[chunk.facadeModuleId!].add(moduleId)
             }
           }
-        return
+          continue
         }
 
-      const id = relativeToSrcDir(chunk.facadeModuleId)
-      for (const file in chunk.modules) {
-        const relativePath = relativeToSrcDir(file)
+        const relativePath = relativeToSrcDir(moduleId)
         if (relativePath in cssMap) {
-          cssMap[relativePath].inBundle = cssMap[relativePath].inBundle ?? !!id
+          cssMap[relativePath].inBundle = cssMap[relativePath].inBundle ?? ((isVue(moduleId) && relativeToSrcDir(moduleId)) || isEntry)
         }
       }
 

packages/vite/src/utils/index.ts

@@ -1,5 +1,7 @@
 import { hash } from 'ohash'
 
+export { isVue } from '../../../nuxt/src/core/utils/plugins'
+
 export function uniq<T> (arr: T[]): T[] {
   return Array.from(new Set(arr))
 }

test/basic.test.ts

@@ -112,7 +112,7 @@ 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>')
+    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>')
     // should register global components automatically
     expect(html).toContain('global component registered automatically')
     expect(html).toContain('global component via suffix')
@@ -1382,6 +1382,8 @@ describe.skipIf(isDev() || isWebpack)('inlining component styles', () => {
     '{--assets:"assets"}', // <script>
     '{--postcss:"postcss"}', // <style lang=postcss>
     '{--scoped:"scoped"}', // <style lang=css>
+    '{--shared-component:"shared-component"}', // styles in a chunk shared between pages
+    '{--server-only-child:"server-only-child"}', // child of a server-only component
     '{--server-only:"server-only"}' // server-only component not in client build
     // TODO: ideally both client/server components would have inlined css when used
     // '{--client-only:"client-only"}', // client-only component not in server build
@@ -1392,7 +1394,7 @@ describe.skipIf(isDev() || isWebpack)('inlining component styles', () => {
   it('should inline styles', async () => {
     const html = await $fetch('/styles')
     for (const style of inlinedCSS) {
-      expect(html).toContain(style)
+      expect.soft(html).toContain(style)
     }
   })
 
@@ -1403,7 +1405,7 @@ describe.skipIf(isDev() || isWebpack)('inlining component styles', () => {
     ]
     const html = await $fetch('/route-rules/spa')
     for (const style of globalCSS) {
-      expect(html).toContain(style)
+      expect.soft(html).toContain(style)
     }
   })
 
@@ -1950,6 +1952,11 @@ describe('component islands', () => {
       expect(result.head).toMatchInlineSnapshot(`
         {
           "link": [
+            {
+              "href": "/_nuxt/components/SharedComponent.vue?vue&type=style&index=0&scoped=3ee84738&lang.css",
+              "key": "island-link",
+              "rel": "stylesheet",
+            },
             {
               "href": "/_nuxt/components/islands/PureComponent.vue?vue&type=style&index=0&scoped=c0c0cf89&lang.css",
               "key": "island-link",

test/fixtures/basic/components/ServerOnlyComponent.server.vue

@@ -5,6 +5,7 @@ prerenderRoutes(['/some/url/from/server-only/component'])
 <template>
   <div>
     server-only component
+    <ServerOnlyComponentChild />
   </div>
 </template>
 

test/fixtures/basic/components/ServerOnlyComponentChild.vue

@@ -0,0 +1,11 @@
+<template>
+  <div>
+    server-only component child (non-server-only)
+  </div>
+</template>
+
+<style>
+:root {
+  --server-only-child: 'server-only-child';
+}
+</style>

test/fixtures/basic/components/SharedComponent.vue

@@ -0,0 +1,9 @@
+<template>
+  <span class="shared-component" />
+</template>
+
+<style scoped>
+.shared-component {
+  --shared-component: 'shared-component';
+}
+</style>

test/fixtures/basic/pages/styles.vue

@@ -3,6 +3,7 @@
     <ClientOnlyScript />
     <FunctionalComponent />
     <ServerOnlyComponent />
+    <SharedComponent />
   </div>
 </template>
 

test/fixtures/basic/pages/vueuse-head.vue

@@ -21,5 +21,7 @@ useLegacyVueUseHead()
 <template>
   <div>
     <h1>VueUse head polyfill test</h1>
+    <!-- This component is only here to make it a shared chunk for test in `styles.vue` -->
+    <SharedComponent />
   </div>
 </template>