Improvements to switch/case exhaustiveness checking

[Firehed]

Feature request

When using the const-as-enum pattern (supported in 0.12.20 via #2904), it would be really helpful to improve several warnings. Turning on strict rules does handle explicitly invalid cases (IMO that should be in the default rules, but that's a different conversation), but defaults get a bit weird:

• Exhausting all switch cases should arguably mark the default case as unreachable
• If all cases have been covered, the lack of a default should not result in a "method xyz should return type but return statement is missing" error
• It would be helpful if the error for case-mismatch was on the case line rather than switch

https://phpstan.org/r/e3457146-1c41-4e70-9740-fe5d67f7f987

[ondrejmirtes]

The third one was easy: phpstan/phpstan-strict-rules@82c19b1

[phpstan-bot]

@Firehed PHPStan now reports different result with your code snippet:

@@ @@
 15: Method C::allCovered() should return int but return statement is missing.
 27: Method C::invalidCase() should return int but return statement is missing.
-27: Switch condition type ('a'|'b'|'c') does not match case condition 'd' (string).
+31: Switch condition type ('a'|'b'|'c') does not match case condition 'd' (string).

Full report

Line	Error
15	Method C::allCovered() should return int but return statement is missing.
27	Method C::invalidCase() should return int but return statement is missing.
31	`Switch condition type ('a'

[devbanana]

Adding my vote to this one. doesn't make sense to require a default in these cases.

[phpstan-bot]

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

@@ @@
-15: Method C::allCovered() should return int but return statement is missing.
-27: Method C::invalidCase() should return int but return statement is missing.
-27: Switch condition type ('a'|'b'|'c') does not match case condition 'd' (string).
+-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

[MidnightDesign]

Somewhere between pre-1.0 and now @phpstan-ignore-next-line stopped working for these cases: https://phpstan.org/r/e1b07d56-dfdc-4f31-b2fe-3ca21b0a94f3

[peldax]

I am current experiencing false positive related to second point you are describing.

Minimal playground: https://phpstan.org/r/b967b249-3d2b-4ed5-9cbb-eadd88777a2c

[ondrejmirtes]

@peldax Your example got fixed: phpstan/phpstan-src#2687

[phpstan-bot]

@peldax After the latest push in 1.11.x, PHPStan now reports different result with your code snippet:

@@ @@
-PHP 8.1 – 8.2 (1 error)
+PHP 8.1 – 8.2
 ==========
 
-11: Function testFunction() should return int but return statement is missing.
+No errors
 
 PHP 7.2 – 8.0 (1 error)
 ==========
 
  3: Syntax error, unexpected T_STRING on line 3

Full report

PHP 8.1 – 8.2

No errors

PHP 7.2 – 8.0 (1 error)

Line	Error
3	Syntax error, unexpected T_STRING on line 3