Bug report

It looks like setting a new property value (after checking its value in an if) does not change the type that PHPStan expects it to be. On local variables works as expected.

if (! $this->code) {
    $this->code = stringOrNull();
    $otherVar = stringOrNull();

    \PHPStan\dumpType($this->code);
    // Dumped type: ''|'0'|null

    \PHPStan\dumpType($otherVar);
    // Dumped type: string|null
}

Problem occurs in PHPStan 2.1.13. No problem in 2.1.12.

Code snippet that reproduces the problem

https://phpstan.org/r/17149323-3d3f-49e8-af7c-8548cbe95d3e

Expected output

Both dumped types should be the same - string|null

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