Okay, here's a revised version, which adds most filesystem functions. file_get_content() is now marked to not have side-effects, which kinda makes sense. However, I'm still a bit unsure about how useful that is. It makes this work though:

if (file_get_contents($path) === 'data') {
	assertType('\'data\'', file_get_contents($path));
	file_put_contents($path, 'other');
	assertType('string|false', file_get_contents($path));
}

Maybe in the future there should be more precise metadata than just "hasSideEffects". Some of these functions would be better described as "volatile". Or perhaps even an interface FunctionSideEffectExtension or something like that.

Hi, thank you! The file you modified is actually generated automatically when running ./bin/generate-function-metadata.php and the result is merged from ./bin/functionMetadata_original.php and by looking at jetbrains/phpstorm-stubs methods and functions with the #[Pure] attribute.

I'd like this course of action instead:

1. Contribute the functions that have 'hasSideEffects' => true as a modification to functionMetadata_original.php.
2. Contribute the #[Pure] functions without side effects to jetbrains/phpstorm-stubs.
3. Once the PR from 2) is merged, please update the package here and run ./bin/generate-function-metadata.php.

Thank you!

This got a bit complicated unfortunately.

The phpstorm-stubs update has been merged. However, updating phpstorm-stubs to the newest master causes a few tests to fail. This is due to a change in phpstorm-stubs, which implements PHP RFC: Add return type declarations for internal methods. That RFC is about adding tentative return type declarations, which as I understand is about return type declarations that only trigger a warning, but aren't fully enforced yet (not until PHP 9.0).

As an example, Countable::count() has now a tentative return type int, causing PHPStan to complain about all implementations that don't have a compatible return type declaration.

I'm not sure what the best course of action here. In the long term, PHPStan should probably parse #[TentativeType] and act on it. For now I'll reduce this PR to only update ./bin/functionMetadata_original.php, it should be enough to fix phpstan/phpstan#5461.

I see that tentative return types have been implemented and the stubs have been updated. I rebased this to fix conflicts.

Thank you!