UndefinedThisPropertyFetch within property_exists() check

[ghost]

I am loading dynamic objects and testing for some properties via property_exists(). Unfortunately, this causes UndefinedThisPropertyFetch errors.

https://psalm.dev/r/0a435e7d65

I tested the same code with phpstan and it produces no errors.

Seems like this is an old issue: #5913

Thank you.

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/0a435e7d65

<?php

class A {
    function test(): void
    {
        
        if(property_exists($this, "foo"))
        	echo "$this->foo";
        
    }
}

Psalm output (using commit f960d71):

ERROR: UndefinedThisPropertyFetch - 8:16 - Instance property A::$foo is not defined

[AndrolGenhald]

I'll close this as a duplicate of #2206, but I hope for this to be possible eventually by intersecting classes with object-with-properties (eg A&object{foo: mixed}) so that property_exists and isset can add properties to an existing class.