Fix XMLReader::open() return type

[jeroennoten]

XMLReader::open() returns an instance of XMLReader when called statically (and according to its ReflectionMethod, XMLReader::open() is actually a static function).

Currently, this method is now unable to use in boths ways without PHPStan reporting errors with strict rules enabled:

• Non-statically: https://phpstan.org/r/3fd6a8b3-3320-4e26-8a81-4f0a4a16c8c9
• Statically: https://phpstan.org/r/6afc7b43-ccd8-4b21-b235-229c46c23603

Actually, an even better fix would be to make the return type dependent on whether the method is called statically or not, is that possible? It returns XMLReader|false when called statically or bool when called non-statically.

[ondrejmirtes]

Actually, an even better fix would be to make the return type dependent on whether the method is called statically or not, is that possible?

This is possible with dynamic return type extensions: https://phpstan.org/developing-extensions/dynamic-return-type-extensions so feel free to contribute one :) There are many examples to learn from in PHPStan's codebase itself: https://github.com/phpstan/phpstan-src/tree/master/src/Type/Php

[jeroennoten]

@ondrejmirtes, I found some time to add a dynamic return type extension for XMLReader::open(). Could you please check if this the right way to do it?

[ondrejmirtes]

Thank you