When implementing global navigation guards using beforeEach, invoking next() with any argument fundamentally alters the execution flow. Rather than completing the current navigation, passing a location object or path string to next() triggers a cancellation of the pending route and initiates an entirely new navigation cycle. This behavior creates a recursive guard execution that resembles nested function calls, where each redirection spawns a fresh instance of the guard until an unconditional next() (invoked without parameters) finally resolves the chain.

Consider a guard that redirects unauthenticated users:

router.beforeEach((to, from, next) => {
  if (to.path === '/admin' && !isAuthenticated) {
    next('/login')
  } else {
    next()
  }
})

When navigating to /admin, the guard interrupts the original navigation and restarts the process targeting /login. This second iteration evaluates the same guard logic, but since /login typically doesn't trigger the authentication check, the guard calls next() without arguments, allowing the router to complete the navigation to the login page.

This interruption mechanism becomes problematic when dynamically registering routes using addRoute(). Immediately after adding routes programmatically—commonly following an authentication check that retrieves user permissions—the route table hasn't stabilized. Attempting to navigate to a freshly added route results in a blank screen because the router hasn't indexed the new route configuration yet.

The standard solution involves recursively retrying the navigation until the dynamic route becomes available:

router.beforeEach(async (to, from, next) => {
  const hasAccess = checkUserPermissions()
  
  if (!hasAccess) {
    next('/unauthorized')
    return
  }
  
  // Dynamically add permission-based routes
  if (!router.hasRoute('dynamicDashboard')) {
    const dynamicRoutes = await fetchRouteConfig()
    dynamicRoutes.forEach(route => router.addRoute(route))
    
    // Retry navigation with current destination
    next({ ...to, replace: true })
    return
  }
  
  // Ensure route exists to prevent infinite recursion
  if (to.matched.length === 0) {
    next({ ...to, replace: true })
  } else {
    next()
  }
})

The replace: true option proves critical here. Without it, each retry generates a new history entry, polluting the browser's session history and potentially trapping users in an unbreakable back-button loop. By setting replace: true, the retry navigation replaces the current history entry rather than appending to it.

Failure to implement proper exit conditions creates an infinite recursion. If the guard continuously calls next({ ...to }) without verifying whether the route now exists, the application enters a navigation deadlock that eventually triggers a stack overflow error. Always verify the route's existence through to.matched.length or router.hasRoute() before attempting a retry.