LanguageConverterFactoryTest.php has the $trivialWithNothingElseCodes array with a long list of language codes that don't have language converters. It appears to test that they don't have converters. Is this actually necessary?

As far as I can tell, it was introduced in https://gerrit.wikimedia.org/r/c/mediawiki/core/+/564789 .

If this is really necessary, then perhaps it should be added to https://www.mediawiki.org/wiki/Manual:Adding_and_removing_languages , so that every new language that is added to Names.php will be added to this array, too.

But if it's not really necessary, then it probably should be greatly reduced. My hunch is just that a few languages without conversion are enough, or even just one, but maybe I'm missing something.