How to check if path alias exists

Question

In Drupal 8, my custom module includes the code

if (\Drupal::service('path.alias_storage')->aliasExists($path, 'en')) {
    return true;
}

What should this look like in Drupal 9.2? Seems so simple, but I can't figure it out after reading every post I can find.

Answer 1

This service was deprecated in Drupal 8 and removed in Drupal 9.

Path aliases were converted to an entity. You can use the entity storage and additionally the path_alias.repository service for some common case-insensitive lookups:

$path_alias_repository = \Drupal::service('path_alias.repository');
if ($path_alias_repository->lookupByAlias($alias, 'en')) {
  return TRUE;
}

Interesting is that the service AliasRepository provides a pathHasMatchingAlias() method but not one for the other direction, so you have to check whether the lookup method above returns a result.