Undefined property on models when using interface

[kyrare]

• Larastan Version: 2.6.3
• --level used: 2
• Pull request with failing test:

Description

Larastan does not see properties that have been checked through the interface

Laravel code where the issue was found

use Illuminate\Database\Eloquent\Model;

/**
 * @property-read string $url
 */
interface Page
{
    public function getUrlAttribute(): string;
}

class News extends Model implements Page
{
    public function getUrlAttribute(): string
    {
        return '/news/foo/';
    }
}

function test(Model $model): array
{
    $data = [];
    
    if ($model instanceof Page) {
        $data[] = $model->url; // Access to an undefined property Illuminate\Database\Eloquent\Model&Page::$url
    }

    return $data;
}

[szepeviktor]

Try using an Accessor
https://laravel.com/docs/10.x/eloquent-mutators#accessors-and-mutators

Then add PHP generics

/**
 * @return \Illuminate\Database\Eloquent\Casts\Attribute<string, never>
 */

[sanfair]

Properties cannot be defined on interfaces
https://phpstan.org/r/f14d865c-30c1-4075-9050-8b11086c1811

Update: link to PHPStan issue phpstan/phpstan#8550