How to get an entity's ->original entity without triggering "Access to an undefined property"

[alberto56]

When a node is in the process of being saved, an entity's ->original property will contain null if the entity is new, or the original entity if the entity is being changed.

However if we have code like:

...
$entity->original;
...

We get the error:

  78     Access to an undefined property                                           
         Drupal\Core\Entity\EntityInterface::$original.                            
         💡 Learn more:                                                            
            https://phpstan.org/blog/solving-phpstan-access-to-undefined-property  

The only way I could find to get rid of this error is to add:

    // @phpstan-ignore-next-line

Is there a better way to access the original property without triggering this error?

[dpi]

Consider running the patch ;) https://www.drupal.org/project/drupal/issues/2839195

[mglaman]

Or, add @property EntityInterface|null $original to https://github.com/mglaman/phpstan-drupal/blob/main/stubs/Drupal/Core/Entity/EntityInterface.stub