False positive when instantiating an object from a string that contains a fully qualified class name

[AlexHowansky]

Bug report

This issue appeared in 0.12.86, and still exists in 0.12.87.

When instantiating a class from a string that contains the class name, PHPStan will error if the class name is fully qualified -- i.e., if it starts with a backslash.

class Foo {}

// works fine
$class = new Foo();

// works fine
$name = 'Foo';
$class = new $name();

// fails with "Instantiated class \Foo not found."
$name = '\Foo';
$class = new $name();

// fails with "Instantiated class \Foo not found."
$name = '\\Foo';
$class = new $name();

https://phpstan.org/r/fb04310a-7e86-45a4-bbdc-c306ccb91f09

Expected output

This is a false positive. No error should be reported.

[s3tezsky]

Hello there, we have a simillar issue to FQCN defined by strings in shopsys. Our issue is a bit different but I belive it is related (as @AlexHowansky we are experiencing it from version 0.12.86).
We have failing standards for creating mocks using FQCN with leading backslash, but there are only some of them reported.

See our output of phpstan:
https://github.com/shopsys/shopsys/pull/2318/checks?check_run_id=2577320726#step:4:406
and code of that build:
https://github.com/shopsys/shopsys/blob/1551dec992ea385a3c4f454bc7589949f2d2a3b0/packages/framework/tests/Unit/Model/Security/AuthenticatorTest.php#L22

As I wrote above, it is strange that not all of those occurences are reported (e.g. see line 18 in the same file).

Cheers!

[ondrejmirtes]

Fixed: phpstan/phpstan-src@428baf5

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.