get_object_vars assumes object does not have properties

[jsiefer]

Example: https://psalm.dev/r/fe5ff75f6a

Hi, the statement would be correct for class A and if it was final, but it should take into account that a class could be extended, or?

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/fe5ff75f6a

<?php

class A { 
}
class B {
    public int $a = 1;
}

function writeDictionary(A $dictionary): void
{
	$values = get_object_vars($dictionary);
	ksort($values, SORT_STRING);
}

Psalm output (using commit 0ded59d):

ERROR: RedundantFunctionCall - 12:2 - The call to ksort is unnecessary, array<never, never> is already a list

[orklah]

indeed, Psalm should not assume a child of the appearing object won't have new properties, unless the class is final.

This is handled here:

psalm/src/Psalm/Internal/Provider/ReturnTypeProvider/GetObjectVarsReturnTypeProvider.php

Line 65 in 97e6511

return Type::getEmptyArray();

(and also two more lines like it in the same file)