Major new feature 🚀

Dependent variables

PHPStan can now understand relationships between different variables. Cases like these are now understood correctly:

if ($debug) {
    $foo = 'bar';
}

if ($debug) {
    // previously: Variable $foo might not be defined.
    // now: no error
    echo $foo;
}

Additionally, this feature fixes all these issues: #801, #806, #1209, #1306, #1722, #1865, #2980, #3371, #3986

Bugfixes 🐛

• Implement property name as an expression in TypesAssignedToPropertiesRule (phpstan/phpstan-src@7458d1e)
• Updated nikic/php-parser (phpstan/phpstan-src@19bf582), #4194

Function signature fixes 🤖

• Changing return type of Collator::compare to int|false (#410), thanks @vasekbrychta!
• Update PHP 8 stubs (phpstan/phpstan-src@4430549), #4268