Nuxt i18n Calling useRoute within middleware may lead to misleading results – Javascript

The Problem:

In Nuxt.js, using useRoute() within a middleware may result in incorrect route information. This warning is triggered by calling useLocalePath() in a middleware, which can lead to misleading outcomes. The middleware should instead utilize the (to, from) arguments passed to it to access the new and old routes, ensuring accurate route handling.

The Solutions:

Solution 1: Use `useNuxtApp()` instead of `useRoute()` in middleware

To fix the warning, replace useRoute() with useNuxtApp() in the middleware. useNuxtApp() provides access to the Nuxt application instance, which includes the $localePath method that can be used to generate localized paths. Here’s the corrected code:

export default defineNuxtRouteMiddleware(async (to, from) => {
  const nuxt = useNuxtApp();

  const isUserAuthenticated = await isAuthenticated();

  if (isUserAuthenticated) {
    if (to.fullPath === nuxt.$localePath('login') || to.fullPath === nuxt.$localePath('register')) {
      return navigateTo(nuxt.$localePath('/'));
    }
  } else {
    if (to.fullPath !== nuxt.$localePath('login') && to.fullPath !== nuxt.$localePath('register')) {
      return navigateTo(nuxt.$localePath('login'));
    }
  }
});

This solution ensures that the $localePath method is accessed correctly within the middleware, preventing the warning and ensuring that localized paths are generated correctly.

Solution 2: Replace useRoute with useI18n or create a reusable composable

To resolve the warning "Calling useRoute within middleware may lead to misleading results," you can replace the use of useRoute() with useI18n() in your middleware function. Here’s an example:

export default defineNuxtRouteMiddleware(async (to, from) => {
  const locale = useNuxtApp().$i18n.locale;

  const isUserAuthenticated = await isAuthenticated();

  if (isUserAuthenticated) {
    if (to.fullPath === locale.value + '/login' || to.fullPath === locale.value + '/register') {
      return navigateTo(locale.value + '/');
    }
  } else {
    if (
      to.fullPath !== locale.value + '/login' &&
      to.fullPath !== locale.value + '/register'
    ) {
      return navigateTo(locale.value + '/login');
    }
  }
});

Alternatively, you can create a reusable composable to generate translated URLs:

export default function useTranslateUrl(url: string): string {
  const locale = useNuxtApp().$i18n.locale;
  return `/${locale.value}${url.startsWith("/") ? url : `/${url}`}`;
}

Using this composable, you can simplify your middleware function as follows:

export default defineNuxtRouteMiddleware(async (to, from) => {
  const isUserAuthenticated = await isAuthenticated();

  if (isUserAuthenticated) {
    if (to.fullPath === useTranslateUrl('login') || to.fullPath === useTranslateUrl('register')) {
      return navigateTo(useTranslateUrl('/'));
    }
  } else {
    if (
      to.fullPath !== useTranslateUrl('login') &&
      to.fullPath !== useTranslateUrl('register')
    ) {
      return navigateTo(useTranslateUrl('/login'));
    }
  }
});

Note: Ensure that your locales are not in the ISO format (en-US) unless your entire i18n configuration is set up that way to avoid potential issues.