Type inference after using array_pop could be improved.

[mad-briller]

Feature request

In the below case, using array_pop makes phpstan believe the $headers value could be an empty array, when prior it knew that there were atleast 4 values.
array_pop always removes one element from the array and as such the second count() value could return int<3, max> in this case, and also persist the non-empty-array type.

https://phpstan.org/r/5003d274-3690-464e-a5e1-6e898cd00411

[herndlm]

The code triggering this is most likely in https://github.com/phpstan/phpstan-src/blob/1.8.2/src/Analyser/NodeScopeResolver.php#L1803-L1831

[thg2k]

Interestingly, if you dump the type of the array before dumping the type of the count, it changes to int<1, max>.

https://phpstan.org/r/892c0769-7920-42cf-9354-69c91b915ef1

Could this be a signal for some other more serious bug? @ondrejmirtes

[mad-briller]

@thg2k i also stumbled across that while debugging and made a separate issue #7803

[phpstan-bot]

@thg2k After the latest push in 1.8.x, PHPStan now reports different result with your code snippet:

@@ @@
  7: Dumped type: int<4, max>
  8: Dumped type: non-empty-array<int, string>
- 9: Dumped type: int<1, max>
+ 9: Dumped type: int<4, max>
 11: Dumped type: int<0, max>

Full report

Line	Error
7	Dumped type: int<4, max>
8	Dumped type: non-empty-array<int, string>
9	Dumped type: int<4, max>
11	Dumped type: int<0, max>