Conditional redirection issue

[rdrglpzcnt]

Hello!
Need to catch THOUSANDS of old users url's matching: ^/([-_.a-zA-Z0-9]+)$
and redirect them to: /user/$1

This is my rule, where app_pages are the app main paths:

let app_pages = [
	...
	'admin',
	'auth',
	'tests',
	'widgets',
	'dev-login',
	'user',
	...
];
...
...
...
{
	from: '^/([-_.a-zA-Z0-9]+)$',
	to: (from, req) => {
		let param = req.url.match(from)[1];
		
		if (app_pages.includes(param)) {
			//PROBLEM HERE: infinite loop
			return '/$1'
		}
		//this route has an asyncData function that checks $1 to show profile or to return 404
		return '/user/$1'
	},
	statusCode: 301
},
...

How can i do something like return next() or not redirecting if it matches an app_pages path?

[rdrglpzcnt]

:(