match() with isset is incorrectly warning about remaining value to use in branch

[tpetry]

PHPStan is checking whether all possible outcomes of a match expression are used. But for isset it's reporting an error despite true and false are used.

Code snippet that reproduces the problem

/// PHPStan: Match expression does not handle remaining value: bool
match (isset($foo)) {
    true => 'a',
    false => 'b',
};

https://phpstan.org/r/4d740289-69d9-4071-825f-014bd4bdfecc

Expected output

The code is correct, as it has a branch for the true and false value.

[rajyan]

This one #6910
and a comments in this PR is related.
It’s a type specifying problem.

[rajyan]

I was on fixing this, but dropped priority because I think ternary operator can be better in these cases.

[ondrejmirtes]

Fixed: phpstan/phpstan-src@3c7d9c8

Technically these issues will be true for all expression types handled above this if statement in MutatingScope::resolveType():

		$exprString = $this->getNodeKey($node);
		if (isset($this->moreSpecificTypes[$exprString]) && $this->moreSpecificTypes[$exprString]->getCertainty()->yes()) {
			return $this->moreSpecificTypes[$exprString]->getType();
		}

But for performance reasons we should move the handling only of those expressions that impact real-world scenarios.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.