Useless null coalesce not reported when relying on class property typehint

[janedbal]

Bug report

Condition always-string ?? 'string' is not reported as useless in following snippet. When passed as argument, it works.

Code snippet that reproduces the problem

Snippet: https://phpstan.org/r/9aa7f36f-d294-404f-849b-590a288ad9fe

Expected output

Useless null coalesce reported

[ondrejmirtes]

This is a very narrow use-case - property with a native typehint that can never be in an uninitialized state.

[janedbal]

Yeah, ideally, it should know which props were initialized (like you do in checkUninitializedProperties) and check accordingly even when the prop does not have default value, but I guess that is hard to do.

[phpstan-bot]

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

@@ @@
-No errors
+-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]

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

@@ @@
- 8: Variable $foo on left side of ?? always exists and is not nullable.
+-1: Internal error: PHPStan\Rules\Methods\WrongCaseOfInheritedMethodRule::findMethod(): Argument #2 ($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]

Closed via merging phpstan/phpstan-src#5327