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Type of child object is not infered if get_class is used outside of switch argument #523
Description
It's hard to explain this issue that I found, so I'll provide a code example:
<?php declare(strict_types = 1);
class Base {}
class Child1 extends Base {}
function typeHintedFunction(Child1 $object)
{
}
function testPasses(Base $object)
{
switch (get_class($object)) {
case Child1::class:
typeHintedFunction($object);
}
$type = get_class($object);
switch ($type) {
case Child1::class:
typeHintedFunction($object);
}
}PHPStan raise an error if I use get_class and assign it to a variable, but not if I do it directly in the switch statement: https://phpstan.org/r/2cc127fa-2762-48a5-8a25-56f326f38451
Activity
ondrejmirtes commentedon Sep 28, 2017
Yep, PHPStan is not that smart yet 😊 Try to make the code more understandable for the static analyzer.
Alternative (also understood) approach is this:
Jean85 commentedon Sep 28, 2017
For now I've just moved the
get_classinside the switch statement since it wasn't an issue, but now that I'm thinking about it, your approach is better performance-wise, since it's not comparting two strings but just checking the type of an instance, which is more correct and faster; thanks!ondrejmirtes commentedon Dec 2, 2020
Closing this in favour of: #1239
ondrejmirtes commentedon Dec 2, 2020
Oh, this is actually for dependent types.
gbirke commentedon Apr 8, 2022
I have made another example where this fails for
get_classinside amatchstatement:https://phpstan.org/r/d6117a8f-0255-479d-b681-e45396ce79df
phpstan-bot commentedon Jun 19, 2023
@gbirke After the latest push in 1.11.x, PHPStan now reports different result with your code snippet:
Full report
PHP 8.0 – 8.1
No errors
PHP 7.1 – 7.4 (3 errors)
Syntax error, unexpected ',' on line 53Syntax error, unexpected T_DOUBLE_ARROW on line 53Syntax error, unexpected '}' on line 55