fix(nuxt): ensure we only increment hydrating count once (#22200)

packages/nuxt/src/app/components/layout.ts

@@ -33,8 +33,9 @@ export default defineComponent({
     const layoutRef = ref()
     context.expose({ layoutRef })
 
-    return () => {
     const done = nuxtApp.deferHydration()
+
+    return () => {
       const hasLayout = layout.value && layout.value in layouts
       if (process.dev && layout.value && !hasLayout && layout.value !== 'default') {
         console.warn(`Invalid layout \`${layout.value}\` selected.`)

packages/nuxt/src/pages/runtime/page.ts

@@ -46,6 +46,8 @@ export default defineComponent({
     const _layoutMeta = inject(LayoutMetaSymbol, null)
     let vnode: VNode
 
+    const done = nuxtApp.deferHydration()
+
     return () => {
       return h(RouterView, { name: props.name, route: props.route, ...attrs }, {
         default: (routeProps: RouterViewSlotProps) => {
@@ -76,7 +78,6 @@ export default defineComponent({
           }
 
           const key = generateRouteKey(routeProps, props.pageKey)
-          const done = nuxtApp.deferHydration()
 
           const hasTransition = !!(props.transition ?? routeProps.route.meta.pageTransition ?? defaultPageTransition)
           const transitionProps = hasTransition && _mergeTransitionProps([

test/basic.test.ts

@@ -1034,6 +1034,16 @@ describe('deferred app suspense resolve', () => {
   it('should wait for all suspense instance on initial hydration', async () => {
     await behaviour('/internal-layout/async-parent/child')
   })
+  it('should fully hydrate even if there is a redirection on a page with `ssr: false`', async () => {
+    const page = await createPage('/hydration/spa-redirection/start')
+    await page.waitForLoadState('networkidle')
+
+    // Wait for all pending micro ticks to be cleared in case hydration hasn't finished yet.
+    await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 10)))
+
+    const html = await page.getByRole('document').innerHTML()
+    expect(html).toContain('fully hydrated and ready to go')
+  })
 })
 
 describe('nested suspense', () => {

test/fixtures/basic/nuxt.config.ts

@@ -48,6 +48,7 @@ export default defineNuxtConfig({
     },
     routeRules: {
       '/route-rules/spa': { ssr: false },
+      '/hydration/spa-redirection/**': { ssr: false },
       '/no-scripts': { experimentalNoScripts: true }
     },
     output: { dir: process.env.NITRO_OUTPUT_DIR },

test/fixtures/basic/pages/hydration/spa-redirection/end.vue

@@ -0,0 +1,12 @@
+<script setup lang="ts">
+const ready = ref('not yet hydrated')
+onNuxtReady(() => {
+  ready.value = 'fully hydrated and ready to go'
+})
+</script>
+
+<template>
+  <div>
+    {{ ready }}
+  </div>
+</template>

test/fixtures/basic/pages/hydration/spa-redirection/start.vue

@@ -0,0 +1,11 @@
+<script setup lang="ts">
+definePageMeta({
+  middleware: () => '/hydration/spa-redirection/end'
+})
+</script>
+
+<template>
+  <div>
+    Tests whether hydration is properly resolved when loading
+  </div>
+</template>