You'll need to add a test :)

Using parse_url would be better IMO

@Tobion If i use parse_url the code should be:

if (in_array(parse_url($uri, PHP_URL_SCHEME), array('http', 'https'))) {
    return $uri;
}

@jakzal How can i test a protected method? via Reflection?

Another option https://github.com/symfony/asset/blob/2.7/Package.php#L68-L71

@jakzal How can i test a protected method? via Reflection?

You don't. You should test its behaviour through a public method.

Closing in favor of #14785 (it has tests).