fix(nuxt): inline global css with `ssr: false` route rule (#21763)

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

@@ -126,6 +126,7 @@ const getSPARenderer = lazyCachedFunction(async () => {
 
   const renderToString = (ssrContext: NuxtSSRContext) => {
     const config = useRuntimeConfig()
+    ssrContext.modules = ssrContext.modules || new Set<string>()
     ssrContext!.payload = {
       _errors: {},
       serverRendered: false,

test/basic.test.ts

@@ -1169,6 +1169,17 @@ describe.skipIf(isDev() || isWebpack)('inlining component styles', () => {
     }
   })
 
+  it('should inline global css when accessing a page with `ssr: false` override via route rules', async () => {
+    const globalCSS = [
+      '{--plugin:"plugin"}', // CSS imported ambiently in JS/TS
+      '{--global:"global";' // global css from nuxt.config
+    ]
+    const html = await $fetch('/route-rules/spa')
+    for (const style of globalCSS) {
+      expect(html).toContain(style)
+    }
+  })
+
   it('should not include inlined CSS in generated CSS file', async () => {
     const html: string = await $fetch('/styles')
     const cssFiles = new Set([...html.matchAll(/<link [^>]*href="([^"]*\.css)">/g)].map(m => m[1]))

test/bundle.test.ts

@@ -35,7 +35,7 @@ describe.skipIf(process.env.SKIP_BUNDLE_SIZE === 'true' || process.env.ECOSYSTEM
 
   it('default server bundle size', async () => {
     stats.server = await analyzeSizes(['**/*.mjs', '!node_modules'], serverDir)
-    expect.soft(roundToKilobytes(stats.server.totalBytes)).toMatchInlineSnapshot('"63.9k"')
+    expect.soft(roundToKilobytes(stats.server.totalBytes)).toMatchInlineSnapshot('"64.0k"')
 
     const modules = await analyzeSizes('node_modules/**/*', serverDir)
     expect.soft(roundToKilobytes(modules.totalBytes)).toMatchInlineSnapshot('"2328k"')