Don't understand phpstan, none of the methods in this test have any return type.

I kinda wonder if this is worth fixing from a performance standpoint, it adds a loop on every multi constraint for a case which will most likely almost never happen as it's really nonsense constraints.. And it's not like it was broken before, it just returns a slightly optimized version now.

I just noticed because I did $constraint instanceof MatchAllConstraint instead of $constraint->matches(new MatchAllConstraint()). Of course the first variant failed which is why I created the PR.

This change is causing a Must provide at least two constraints for a MultiConstraint error, because now that there is an unset($constraints[$k]), the array can become empty after the existing \count($constraints) checks.

        if (0 === \count($constraints)) {
            return new MatchAllConstraint();
        }

        if (1 === \count($constraints)) {
             return $constraints[0];
        }

        foreach ($constraints as $k => $constraint) {
            if ($constraint instanceof MatchAllConstraint) {
                if (!$conjunctive) {
                    return new MatchAllConstraint();
                }
                unset($constraints[$k]);
            }
        }

        // Due to the new unset() above, $constraints can have 0 or 1 member(s) here again,
        // so the checks from above might have to be moved here or copied here.

        $optimized = self::optimizeConstraints($constraints, $conjunctive);

Ah yes.. 84ce71b should fix this I believe

Unfortunately, it does not: PHP Warning: Undefined array key 0 in vendor/composer/semver/src/Constraint/MultiConstraint.php on line 238

return reset($constraints) fixes the issue for me, but I‘m not sure if it is correct.

Yeah reset works, but unfortunately in more complex cases this will still blow up in optimizeConstraint, we'd have to call array_values always there to make sure we have a packed array without gaps for the for loop to work.

I think I will just revert this and done. It was already not really worth it to begin with, but it's only getting worse.

Thank you. 👍