Match expression does not handle remaining value with an array value

[jkuchar]

Bug report

match() definitely handles all values, but phpstan do not think so.

Code snippet that reproduces the problem

https://phpstan.org/r/b07c57ab-5084-4149-9c8b-21c1e14d2377

Expected output

No error.

[phpstan-bot]

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

@@ @@
 PHP 8.0 (1 error)
 ==========
 
- 9: Match expression does not handle remaining value: array(bool, bool)
+-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
 
 PHP 7.4 (4 errors)
 ==========

Full report

PHP 8.0 (1 error)

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

PHP 7.4 (4 errors)

Line	Error
10	Syntax error, unexpected T_DOUBLE_ARROW on line 10
11	Syntax error, unexpected T_DOUBLE_ARROW on line 11
12	Syntax error, unexpected T_DOUBLE_ARROW on line 12
13	Syntax error, unexpected T_DOUBLE_ARROW on line 13

PHP 7.1 – 7.3 (5 errors)

Line	Error
7	Syntax error, unexpected ':' on line 7
10	Syntax error, unexpected T_DOUBLE_ARROW on line 10
11	Syntax error, unexpected T_DOUBLE_ARROW on line 11
12	Syntax error, unexpected T_DOUBLE_ARROW on line 12
13	Syntax error, unexpected T_DOUBLE_ARROW on line 13

[phpstan-bot]

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

@@ @@
 PHP 8.0 (1 error)
 ==========
 
- 9: Match expression does not handle remaining value: array(bool, bool)
+ 5: Method HelloWorld::sayHello() should return int but return statement is missing.
 
 PHP 7.4 (4 errors)
 ==========

Full report

PHP 8.0 (1 error)

Line	Error
5	Method HelloWorld::sayHello() should return int but return statement is missing.

PHP 7.4 (4 errors)

Line	Error
10	Syntax error, unexpected T_DOUBLE_ARROW on line 10
11	Syntax error, unexpected T_DOUBLE_ARROW on line 11
12	Syntax error, unexpected T_DOUBLE_ARROW on line 12
13	Syntax error, unexpected T_DOUBLE_ARROW on line 13

PHP 7.1 – 7.3 (5 errors)

Line	Error
7	Syntax error, unexpected ':' on line 7
10	Syntax error, unexpected T_DOUBLE_ARROW on line 10
11	Syntax error, unexpected T_DOUBLE_ARROW on line 11
12	Syntax error, unexpected T_DOUBLE_ARROW on line 12
13	Syntax error, unexpected T_DOUBLE_ARROW on line 13

[solverat]

same goes for string:

$value *= match ($identifier) {
  'g', 'm', 'k' => 1024,
};

https://phpstan.org/r/37736108-b211-4406-a94e-cec1e5b14c18

[ondrejmirtes]

@solverat Your issue is unrelated, and the reported error is legit. If someone passes 'a' into your method, the match expression will throw an exception. You can either handle all possible strings, or use advanced types in PHPDocs: https://phpstan.org/writing-php-code/phpdoc-types#literals-and-constants

[solverat]

@ondrejmirtes damn you're right - I guess I misinterpreted the message then. Thanks for clarifying!

[phpstan-bot]

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

@@ @@
 PHP 8.0 (1 error)
 ==========
 
- 9: Match expression does not handle remaining value: array(bool, bool)
+ 9: Match expression does not handle remaining value: array{bool, bool}
 
 PHP 7.4 (4 errors)
 ==========

Full report

PHP 8.0 (1 error)

Line	Error
9	Match expression does not handle remaining value: array{bool, bool}

PHP 7.4 (4 errors)

Line	Error
10	Syntax error, unexpected T_DOUBLE_ARROW on line 10
11	Syntax error, unexpected T_DOUBLE_ARROW on line 11
12	Syntax error, unexpected T_DOUBLE_ARROW on line 12
13	Syntax error, unexpected T_DOUBLE_ARROW on line 13

PHP 7.1 – 7.3 (5 errors)

Line	Error
7	Syntax error, unexpected ':' on line 7
10	Syntax error, unexpected T_DOUBLE_ARROW on line 10
11	Syntax error, unexpected T_DOUBLE_ARROW on line 11
12	Syntax error, unexpected T_DOUBLE_ARROW on line 12
13	Syntax error, unexpected T_DOUBLE_ARROW on line 13

[da-mask]

For those who come from google, you probably just want to add a default arm to your match expression.

[eexit]

AFAIK, the default pattern is not mandatory so PHPStan should allow expressions when it's missing.

[allan-simon]

AFAIK, the default pattern is not mandatory so PHPStan should allow expressions when it's missing.

exactly currently we have to do this

        default => throw new UnhandledMatchError($type),

to please phpstan while keeping the default (no pun intended) behaviour

[mostafa-rz]

same for spaceship operator

return match ($foo <=> $bar) {
            1 => TrendEnum::UP,
            0 => TrendEnum::NEUTRAL,
            -1 => TrendEnum::DOWN,
        };

https://phpstan.org/r/71c1b6b0-cab7-49e4-8f3a-813900ba68e4

[phpstan-bot]

@mostafa-rz After the latest commit in 1.7.x, PHPStan now reports different result with your code snippet:

@@ @@
-PHP 8.1 (1 error)
+PHP 8.1
 ==========
 
-16: Match expression does not handle remaining value: int<-1, 1>
+No errors
 
 PHP 7.1 – 8.0 (2 errors)
 ==========

Full report

PHP 8.1

No errors

PHP 7.1 – 8.0 (2 errors)

Line	Error
2	Syntax error, unexpected T_STRING on line 2
4	Syntax error, unexpected T_CASE on line 4

[SomeBdyElse]

I agree with #4451 (comment) that it should be possible to use the default "\UnhandeledMatchError" without explicitly adding a default case.

[ondrejmirtes]

@SomeBdyElse There's a feature request about this: #8042 (it has a hint on how to implement it)