Bug Report

Minimal PHP Code Causing Issue

See https://getrector.com/demo/613f6ed1-6961-4926-9878-82c0c48a8e41

class Project {
    private $name;

    public function __construct(mixed $name) {
        if ($name === null) {
            $name = 'default';
        }
        $this->name = $name;
    }
}

$project = new Project(['name' => 123]);

Responsible rules

• TypedPropertyFromStrictConstructorRector

Expected Behavior

Rector is incorrectly assuming it's safe to convert the type of the property $name to string, even though the constructor can take in any value. Setting the parameter type for the constructor to mixed` or leaving it unspecified has the same incorrect behaviour.

This but doesn't occur if you

• change the if to if ($name === null) { $this->name = 'default'; } else { $this->name = $name; }
• change the if to a ternary $this->name = $name === null ? 'default' : $name;
• change the constructor to take a $name of type int (then it correctly changes the property $name to be int | string).

This obviously is concerning as this appears to do exactly what is specified wouldn't happen in https://getrector.com/blog/new-in-rector-015-complete-safe-and-known-type-declarations, namely that it won't add types it can't know are correct.