False positive with when using in_array with literals (or constants)

[faizanakram99]

Bug report

latest version (reproduced at phpstan.org)

See line 22 of attached snippet, the array is missing 'auto' value yet phpstan reports that \in_array('auto', $propagation, true) will always return true (at line 18)

Code snippet that reproduces the problem

https://phpstan.org/r/00e38865-bbc2-4373-8655-e2f1a3c6c14a

Expected output

No errors

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[staabm]

let me share my current observations:

phpstan runs into this return true case, which leads to the assumption that the value will always be true:

https://github.com/phpstan/phpstan-src/blob/8cc6e7e03b105124686ad4707d57ef818d456347/src/Rules/Comparison/ImpossibleCheckTypeHelper.php#L201

this effectively means UnionType->isSuperTypeOf(ConstantStringType) or
pseudocode: 'auto'|'copy'->isSuperTypeOf('auto')
returns Trinary::yes()

the way to solve this issue is to make sure we actually return null from within https://github.com/phpstan/phpstan-src/blob/8cc6e7e03b105124686ad4707d57ef818d456347/src/Rules/Comparison/ImpossibleCheckTypeHelper.php#L85-L134 so phpstan returns early from findSpecifiedType

[phpstan-bot]

@faizanakram99 After the latest commit in dev-master, PHPStan now reports different result with your code snippet:

@@ @@
-18: Call to function in_array() with arguments 'auto', array<string, 'auto'|'copy'> and true will always evaluate to true.
+-1: Internal error: PHPStan\Rules\Methods\WrongCaseOfInheritedMethodRule::findMethod(): Argument #2 ($classReflection) must be of type PHPStan\Reflection\ClassReflection, null given, called in /var/task/vendor/phpstan/phpstan-strict-rules/src/Rules/Methods/WrongCaseOfInheritedMethodRule.php on line 40
+Run PHPStan with --debug option and post the stack trace to:
+https://github.com/phpstan/phpstan/issues/new?template=Bug_report.md

Full report

Line

Error

-1

Internal error: PHPStan\Rules\Methods\WrongCaseOfInheritedMethodRule::findMethod(): Argument #2 ($classReflection) must be of type PHPStan\Reflection\ClassReflection, null given, called in /var/task/vendor/phpstan/phpstan-strict-rules/src/Rules/Methods/WrongCaseOfInheritedMethodRule.php on line 40Run PHPStan with --debug option and post the stack trace to:https://github.com/phpstan/phpstan/issues/new?template=Bug_report.md

[phpstan-bot]

@faizanakram99 After the latest commit in dev-master, PHPStan now reports different result with your code snippet:

@@ @@
-18: Call to function in_array() with arguments 'auto', array<string, 'auto'|'copy'> and true will always evaluate to true.
+No errors

[ondrejmirtes]

Fixed: phpstan/phpstan-src@4321374

[github-actions]

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