fix(nuxt): handle relative baseURL in nitro runtime config (#23841)

packages/nuxt/src/app/composables/manifest.ts

@@ -1,10 +1,11 @@
-import { joinURL } from 'ufo'
 import type { MatcherExport, RouteMatcher } from 'radix3'
 import { createMatcherFromExport } from 'radix3'
 import { defu } from 'defu'
-import { useAppConfig, useRuntimeConfig } from '#app'
+import { useAppConfig } from '#app'
 // @ts-expect-error virtual file
 import { appManifest as isAppManifestEnabled } from '#build/nuxt.config.mjs'
+// @ts-expect-error virtual file
+import { buildAssetsURL } from '#build/paths.mjs'
 
 export interface NuxtAppManifestMeta {
   id: string
@@ -23,10 +24,9 @@ function fetchManifest () {
   if (!isAppManifestEnabled) {
     throw new Error('[nuxt] app manifest should be enabled with `experimental.appManifest`')
   }
-  const config = useRuntimeConfig()
   // @ts-expect-error private property
   const buildId = useAppConfig().nuxt?.buildId
-  manifest = $fetch<NuxtAppManifest>(joinURL(config.app.cdnURL || config.app.baseURL, config.app.buildAssetsDir, `builds/meta/${buildId}.json`))
+  manifest = $fetch<NuxtAppManifest>(buildAssetsURL(`builds/meta/${buildId}.json`))
   manifest.then((m) => {
     matcher = createMatcherFromExport(m.matcher)
   })

packages/nuxt/src/app/plugins/check-outdated-build.client.ts

@@ -1,18 +1,18 @@
-import { joinURL } from 'ufo'
 import type { NuxtAppManifestMeta } from '#app'
-import { defineNuxtPlugin, getAppManifest, onNuxtReady, useRuntimeConfig } from '#app'
+import { defineNuxtPlugin, getAppManifest, onNuxtReady } from '#app'
+// @ts-expect-error virtual file
+import { buildAssetsURL } from '#build/paths.mjs'
 
 export default defineNuxtPlugin((nuxtApp) => {
   if (import.meta.test) { return }
 
   let timeout: NodeJS.Timeout
-  const config = useRuntimeConfig()
 
   async function getLatestManifest () {
     const currentManifest = await getAppManifest()
     if (timeout) { clearTimeout(timeout) }
     timeout = setTimeout(getLatestManifest, 1000 * 60 * 60)
-    const meta = await $fetch<NuxtAppManifestMeta>(joinURL(config.app.cdnURL || config.app.baseURL, config.app.buildAssetsDir, 'builds/latest.json'))
+    const meta = await $fetch<NuxtAppManifestMeta>(buildAssetsURL('builds/latest.json'))
     if (meta.id !== currentManifest.id) {
       // There is a newer build which we will let the user handle
       nuxtApp.hooks.callHook('app:manifest:update', meta)

packages/nuxt/src/core/nitro.ts

@@ -11,7 +11,7 @@ import escapeRE from 'escape-string-regexp'
 import { defu } from 'defu'
 import fsExtra from 'fs-extra'
 import { dynamicEventHandler } from 'h3'
-import type { Nuxt } from 'nuxt/schema'
+import type { Nuxt, RuntimeConfig } from 'nuxt/schema'
 // @ts-expect-error TODO: add legacy type support for subpath imports
 import { template as defaultSpaLoadingTemplate } from '@nuxt/ui-templates/templates/spa-loading-icon.mjs'
 
@@ -99,6 +99,12 @@ export async function initNitro (nuxt: Nuxt & { _nitro?: Nitro }) {
     },
     runtimeConfig: {
       ...nuxt.options.runtimeConfig,
+      app: {
+        ...nuxt.options.runtimeConfig.app,
+        baseURL: nuxt.options.runtimeConfig.app.baseURL.startsWith('./')
+          ? nuxt.options.runtimeConfig.app.baseURL.slice(1)
+          : nuxt.options.runtimeConfig.app.baseURL
+      } satisfies RuntimeConfig['app'],
       nitro: {
         envPrefix: 'NUXT_',
         ...nuxt.options.runtimeConfig.nitro

test/bundle.test.ts

@@ -19,7 +19,7 @@ describe.skipIf(process.env.SKIP_BUNDLE_SIZE === 'true' || process.env.ECOSYSTEM
   for (const outputDir of ['.output', '.output-inline']) {
     it('default client bundle size', async () => {
       const clientStats = await analyzeSizes('**/*.js', join(rootDir, outputDir, 'public'))
-      expect.soft(roundToKilobytes(clientStats.totalBytes)).toMatchInlineSnapshot('"99.3k"')
+      expect.soft(roundToKilobytes(clientStats.totalBytes)).toMatchInlineSnapshot('"99.2k"')
       expect(clientStats.files.map(f => f.replace(/\..*\.js/, '.js'))).toMatchInlineSnapshot(`
         [
           "_nuxt/entry.js",