fix: redirects to wrong route after SPA navigation

Since 'route' object can be different in a plugin and in a middleware (as
plugin runs once and on further SPA navigations only middleware runs),
we need to use 'route' object from middleware when calling setLocale()
API. Save the route in internal property so that it's always available
to the API.

Before latest refactorings, plugin and middleware has handled it
separately with duplicated code so it wasn't a problem.

src/plugins/main.js

@@ -161,6 +161,7 @@ export default async (context) => {
     await syncVuex(newLocale, app.i18n.getLocaleMessage(newLocale))
 
     if (!initialSetup && STRATEGY !== STRATEGIES.NO_PREFIX) {
+      const route = app.i18n.__route
       const routeName = route && route.name ? app.getRouteBaseName(route) : 'index'
 
       redirect(app.localePath(Object.assign({}, route , {
@@ -181,6 +182,9 @@ export default async (context) => {
   app.i18n.getLocaleCookie = getLocaleCookie
   app.i18n.setLocale = (locale) => loadAndSetLocale(locale)
 
+  // Current route. Updated from middleware also.
+  app.i18n.__route = route
+
   // Extension of Vue
   if (!app.$t) {
     app.$t = app.i18n.t

src/templates/middleware.js

@@ -34,6 +34,9 @@ middleware['i18n'] = async (context) => {
     return
   }
 
+  // Update for setLocale to have up to date route
+  app.i18n.__route = route
+
   // Handle browser language detection
   const detectBrowserLanguage = <%= JSON.stringify(options.detectBrowserLanguage) %>
   const routeLocale = getLocaleFromRoute(route, routesNameSeparator, defaultLocaleRouteNameSuffix, locales)