fix: routing on prefix_and_default strategy (#2235)

specs/fixtures/issues/2226/app.vue

@@ -0,0 +1,22 @@
+<template>
+  <div class="lang-switcher">
+    <div id="default-locale">Default locale: {{ selectedLocale === defaultLocale }}</div>
+    <NuxtLink id="lang-switch" :to="switchLocalePath(availableLocale)">Switch</NuxtLink>
+  </div>
+  <div id="content">
+    <NuxtPage />
+  </div>
+</template>
+
+<script setup>
+const { locale: selectedLocale, defaultLocale, locales } = useI18n()
+const switchLocalePath = useSwitchLocalePath()
+
+const availableLocale = computed(() => locales.value.find(locale => locale !== selectedLocale.value))
+</script>
+
+<style scoped>
+.lang-switcher {
+  margin-bottom: 30px;
+}
+</style>

specs/fixtures/issues/2226/i18n.config.ts

@@ -0,0 +1,4 @@
+export default defineI18nConfig(() => ({
+  legacy: false,
+  locale: 'en'
+}))

specs/fixtures/issues/2226/nuxt.config.ts

@@ -0,0 +1,8 @@
+export default defineNuxtConfig({
+  modules: ['@nuxtjs/i18n'],
+  i18n: {
+    locales: ['en', 'de'],
+    defaultLocale: 'en',
+    strategy: 'prefix_and_default'
+  }
+})

specs/fixtures/issues/2226/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "nuxt3-test-issues-2226",
+  "private": true,
+  "scripts": {
+    "build": "nuxt build",
+    "dev": "nuxt dev",
+    "generate": "nuxt generate",
+    "preview": "nuxt preview"
+  },
+  "devDependencies": {
+    "@nuxtjs/i18n": "latest",
+    "nuxt": "latest"
+  }
+}

specs/fixtures/issues/2226/pages/about.vue

@@ -0,0 +1,8 @@
+<template>
+  This is about page.
+  <NuxtLink id="goto-index" :to="localePath({ name: 'index' })">To home page</NuxtLink>
+</template>
+
+<script setup>
+const localePath = useLocalePath()
+</script>

specs/fixtures/issues/2226/pages/index.vue

@@ -0,0 +1,8 @@
+<template>
+  This is home page.
+  <NuxtLink id="goto-about" :to="localePath({ name: 'about' })">To about page</NuxtLink>
+</template>
+
+<script setup>
+const localePath = useLocalePath()
+</script>

specs/issues/2226.spec.ts

@@ -0,0 +1,29 @@
+import { test, expect, describe } from 'vitest'
+import { fileURLToPath } from 'node:url'
+import { setup, createPage, url } from '../utils'
+import { getText } from '../helper'
+
+describe('#2226', async () => {
+  await setup({
+    rootDir: fileURLToPath(new URL(`../fixtures/issues/2226`, import.meta.url))
+  })
+
+  test('navigate on `prefix_and_default`', async () => {
+    const home = url('/')
+    const page = await createPage()
+    await page.goto(home)
+
+    await page.locator('#lang-switch').click()
+    expect(await getText(page, '#default-locale')).include(`Default locale: false`)
+
+    await page.locator('#goto-about').click()
+    expect(await getText(page, '#content')).include(`This is about page. To home page`)
+
+    await page.locator('#goto-index').click()
+    expect(await getText(page, '#content')).include(`This is home page. To about pag`)
+
+    await page.locator('#lang-switch').click()
+    await page.locator('#goto-about').click()
+    expect(await getText(page, '#content')).include(`This is about page. To home page`)
+  })
+})

src/runtime/utils.ts

@@ -303,11 +303,10 @@ export function detectRedirect<Context extends NuxtApp = NuxtApp>(
     // locale, in which case we might still redirect as we prefer unprefixed route in this case.
     (routeLocaleGetter(route) !== targetLocale || (strategy === 'prefix_and_default' && targetLocale === defaultLocale))
   ) {
-    // the current route could be 404 in which case attempt to find matching route using the full path since
-    // "switchLocalePath" can only find routes if the current route exists.
     const { fullPath } = route
     const decodedRoute = decodeURI(fullPath)
-    const routePath = context.$switchLocalePath(targetLocale) || context.$localePath(fullPath, targetLocale)
+    // the current route could be 404 in which case attempt to find matching route using the full path
+    const routePath = context.$localePath(fullPath, targetLocale)
     __DEBUG__ && console.log('detectRedirect: calculate routePath -> ', routePath, fullPath)
     if (
       isString(routePath) &&