Replace typehint of getConfig with docblock to allow overriding

[tomasfejfar]

Currently you can't override getConfig(): MyCustomConfig as it must be compatible with getConfig(): BaseConfig.

• Failing: https://3v4l.org/QWY1M
• Works like this: https://3v4l.org/aVgmG
• PhpStan complains, but we could ignore it: https://phpstan.org/r/6a146d7a-2439-411f-8ad5-74b4f9df55c7
• PHPStan does not complain (I forgot ChildReturn extends ParentReturn - to make it covariant) https://phpstan.org/r/359a65e0-b9b3-4279-96a0-94e0d00be951

[zajca]

What about return ConfigInterface.
Only getAction method is not listed in interface and used by BaseComponent.
//edit sorry this also not allows typehint now :-[

Also if it's covariant than PHP 7.4 is behind the door https://wiki.php.net/rfc/covariant-returns-and-contravariant-parameters 🎆

[tomasfejfar]

I know about 7.4, but I thought this would make is possible to implement even in legacy code. Even now we have some components that run 7.1 (less used ones, that would not gain anything by upgrading).

[odinuv]

php 7.1 reached eol, 7.2. is very near https://www.php.net/supported-versions.php