wp-admin/includes/upgrade.php:3620Translate user level to user role name.
$levelintstringfunction translate_level_to_role( $level ) { switch ( $level ) { case 10: case 9: case 8: return 'administrator'; case 7: case 6: case 5: return 'editor'; case 4: case 3: case 2: return 'author'; case 1: return 'contributor'; case 0: default: return 'subscriber'; }}Introduced in 2.0.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/upgrade.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.