Accept ::class as literal string

[staabm]

closes phpstan/phpstan#7823
closes phpstan/phpstan-doctrine#332

[ondrejmirtes]

I disagree with this fix. class-string isn't always literal string.
Rather than that, $x::class should be an intersection with literal-string. You can implement that in MutatingScope::resolveType() and also verify that in NodeScopeResolverTest.

[VincentLanglet]

I disagree with this fix. class-string isn't always literal string.

@craigfrancis didn't give an example of class-string which are not literal-string in phpstan/phpstan-doctrine#332 (comment)

But I think we should follow the way it's handled by psalm
https://psalm.dev/r/16085bfd30

[ondrejmirtes]

// $s is string
if (class_exists($s)) {
    // should $s suddenly be a literal-string?
}

[craigfrancis]

[I’m out atm, and using phone, will try to check properly later]

The source of the variable has to be a literal, so if you got it from example::class, that’s fine… but if you’re checking the value contains a string that happens to match a class name (e.g. ‘class_exists()’), that doesn’t flip the variable to being a literal.

[ondrejmirtes]

That's what I thought, so this PR has to be fixed with my suggestion. Thank you.

[staabm]

thanks for the input guys. I just committed an update.

[staabm]

The spurious out of memory error could also be observed on other PRs. I don‘t think it is related to the actual change

[rvanvelzen]

ConstantStringType is already considered to be a literal string, so intersecting with AccessoryLiteralStringType will just remove the AccessoryLiteralStringType again.

[staabm]

great catch! fixed

[ondrejmirtes]

I'd say that the ifs above should also be covered by this PR. Basically any $obj::class is a literal-string.

So with $obj::class and $obj being EnumCaseObjectType, it should also be literal-string. And with $type instanceof TemplateType && !$type instanceof TypeWithClassName that should work too.

[staabm]

adjusted per feedback.

I am thinking whether a object typed parameter on which ::class is appended should also be considered literal?

/**
 * @param object $o
 */
function a($o): void
{
	assertType('class-string&literal-string', $o::class);
	sayHello($o::class);
}

[ondrejmirtes]

Of course :)

[ondrejmirtes]

Please rebase and solve the conflict, I'll merge it then.

[ondrejmirtes]

Thank you!