False positive in composer

[greew]

Bug report

After upgrading to 1.10.37, a new false positive has surfaced in https://github.com/composer/composer/blob/main/src/Composer/Command/DiagnoseCommand.php#L702

I have reproduced the bug in the playground.

If I

• remove line 5-7
• change line 11 to a simple else
• remove the the empty check (line 15)
  the error doesn't appear. It takes this specific setup to make it appear.

Code snippet that reproduces the problem

https://phpstan.org/r/5eb1279c-18a6-4243-ad3c-7d223a68f8c4

Expected output

I expected

 ------ -----------------------------------------------------------------------------
  Line   test.php
 ------ -----------------------------------------------------------------------------
  15     Construct empty() is not allowed. Use more strict comparison.
 ------ -----------------------------------------------------------------------------

but got

 ------ -----------------------------------------------------------------------------
  Line   test.php
 ------ -----------------------------------------------------------------------------
  15     Construct empty() is not allowed. Use more strict comparison.
  19     Switch condition type ('a'|'c') does not match case condition 'b' (string).
 ------ -----------------------------------------------------------------------------

Did PHPStan help you today? Did it make you happy in any way?

Thank you for a great product!

[Seldaek]

It seems to me the problem is in the handling of empty(), this with debug output highlights well how after empty it has merged the 3 states (empty array, array with a+b or array with a+c) into one non empty array with a+c but b is gone.

https://phpstan.org/r/3974e839-40bf-4176-b035-2acea52390c3

[greew]

Great! Thank you for helping with how the debug works. I haven't tried it before! :)

[ondrejmirtes]

Fixed, gonna release PHPStan 1.10.38 with this fix soon: phpstan/phpstan-src@746de74

[Seldaek]

No rush for me :) But thanks!

[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.