Assert function failing for Mongo ODM EmbedMany tag

[eastern-ravindra]

https://github.com/doctrine/doctrine-laminas-hydrator/blame/81ee8121f42dcc0b6f39e08dce56b10baf6fb95f/src/DoctrineObject.php#L355

if ($metadata->hasAssociation($field)) {
                $target = $metadata->getAssociationTargetClass($field);
                assert($target !== null);

Above assert code is failing for mongoDB, when we are using EmbedMany argument without target document locally.

According to documentation, EmbedMany without target document is allowed to embed different documents in same field.(https://www.doctrine-project.org/projects/doctrine-mongodb-odm/en/2.7/reference/embedded-mapping.html#mixing-document-types)

Does this assert check is really needed as null value is also accepted for mongodb?

[TomHAnderson]

If you take out the assertion, does it work? There is this line too that expects the target:

doctrine-laminas-hydrator/src/DoctrineObject.php

Line 373 in 81ee812

$this->toMany($object, $field, $target, $value);

[eastern-ravindra]

If you take out the assertion, does it work? There is this line too that expects the target:

doctrine-laminas-hydrator/src/DoctrineObject.php

Line 373 in 81ee812

$this->toMany($object, $field, $target, $value);

toMany function is not working in this case, giving

Doctrine\Persistence\Mapping\MappingExceptionClass '' does not exist

I think, we need to override this function where we can add conditions if $target is null

[driehle]

@eastern-ravindra

The code you are refering to is in the hydration section, i.e. at the place where an array-like input is converted into an object. To convert something into an object, you need to know that type of object (i.e. what class) it shall be. In case of @EmbedMany from MongoDB ODM, this information is not available from the metadata, since it can literally be any document.

I am wondering what you expect from this library. How would you like the hydration result to look like? If not even Doctrine knows the type the object should become, how should this library know?

One could think of a workaround, the the data is hydrated into a stdClass object. That, however, would not be very helpful as you likely could not pass this information to the DocumentManager anymore. If I am not mistaken, the DocumentManager (similar to the EntityManager in ORM) expects all objects to be instances of classes annotated with @Document, so you could not store an object of stdClass.