Fix optional embedded model definition

[art049]

Fixes #272

[michallowasrzechonek-silvair]

FYI I think there is another issue here:

async def test_embedded_model_with_filled_optional(aio_engine: AIOEngine):
    class In(EmbeddedModel):
        a: int

    class Out(Model):
        inner: Union[In, None]

    instance = Out(inner=In(a=3))
    await aio_engine.save(instance)
    fetched = await aio_engine.find_one(Out)
    assert instance == fetched

fails on revision 002f698 with

aio_engine = <odmantic.engine.AIOEngine object at 0x7f58da0b5b10>

    async def test_embedded_model_with_filled_optional(aio_engine: AIOEngine):
        class In(EmbeddedModel):
            a: int
    
        class Out(Model):
            inner: Union[In, None]
    
        instance = Out(inner=In(a=3))
>       await aio_engine.save(instance)

tests/integration/test_embedded_model.py:340: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
odmantic/engine.py:588: in save
    await self._save(instance, local_session)
odmantic/engine.py:534: in _save
    doc = instance.doc(include=fields_to_update)
odmantic/model.py:784: in doc
    doc = self.__doc(raw_doc, type(self), include)
odmantic/model.py:755: in __doc
    self.__doc(item, field.model) for item in raw_doc[field_name]
odmantic/model.py:755: in <listcomp>
    self.__doc(item, field.model) for item in raw_doc[field_name]
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = Out(id=ObjectId('635bb09c1116fe2dbfe2fd2a'), inner=In(a=3)), raw_doc = 'a', model = <class 'tests.integration.test_embedded_model.test_embedded_model_with_filled_optional.<locals>.In'>, include = None

    def __doc(
        self,
        raw_doc: Dict[str, Any],
        model: Type["_BaseODMModel"],
        include: Optional["AbstractSetIntStr"] = None,
    ) -> Dict[str, Any]:
        doc: Dict[str, Any] = {}
        for field_name, field in model.__odm_fields__.items():
            if include is not None and field_name not in include:
                continue
            if isinstance(field, ODMReference):
                doc[field.key_name] = raw_doc[field_name][field.model.__primary_field__]
            elif isinstance(field, ODMEmbedded):
                doc[field.key_name] = self.__doc(raw_doc[field_name], field.model, None)
            elif isinstance(field, ODMEmbeddedGeneric):
                if raw_doc[field_name] is None:
                    doc[field.key_name] = None
                elif field.generic_origin is dict:
                    doc[field.key_name] = {
                        item_key: self.__doc(item_value, field.model)
                        for item_key, item_value in raw_doc[field_name].items()
                    }
                else:
                    doc[field.key_name] = [
                        self.__doc(item, field.model) for item in raw_doc[field_name]
                    ]
            elif field_name in model.__bson_serialized_fields__:
                doc[field.key_name] = model.__fields__[field_name].type_.__bson__(
                    raw_doc[field_name]
                )
            else:
>               doc[field.key_name] = raw_doc[field_name]
E               TypeError: string indices must be integers

[michallowasrzechonek-silvair]

Moreover:

async def test_parse_embedded_model_with_filled_optional():
    class In(EmbeddedModel):
        a: int

    class Out(Model):
        inner: Union[In, None]

    instance = Out.parse_doc({"_id": "5a6a43a5ca40d8defe2bf4e0", "inner": {"a": 3}})

also fails:

cls = <class 'tests.integration.test_embedded_model.test_parse_embedded_model_with_filled_optional.<locals>.Out'>, raw_doc = {'_id': '5a6a43a5ca40d8defe2bf4e0', 'inner': {'a': 3}}

    @classmethod
    def parse_doc(cls: Type[BaseT], raw_doc: Dict) -> BaseT:
        """Parse a BSON document into an instance of the Model
    
        Args:
            raw_doc: document to parse (as Dict)
    
        Raises:
            DocumentParsingError: the specified document is invalid
    
        Returns:
            an instance of the Model class this method is called on.
        """
        errors, obj = cls._parse_doc_to_obj(raw_doc)
        if len(errors) > 0:
            raise DocumentParsingError(
                errors=[errors],
                model=cls,
>               primary_value=raw_doc.get("_id", "<unknown>"),
            )
E           odmantic.exceptions.DocumentParsingError: 1 validation error for Out
E           inner
E             incorrect generic embedded model value (type=value_error.incorrectgenericembeddedmodelvalue; value={'a': 3})
E           (Out instance details: id='5a6a43a5ca40d8defe2bf4e0')

[adeelsohailahmed]

Hi @art049,

As always, thank you for all the work you do.

The issues (as described in the comments here), as well the original #272 issue are still preventing us from upgrading ODMantic to the latest version.

[gsakkis]

@art049 @michallowasrzechonek-silvair @adeelsohailahmed I submitted a new PR for this. It works for me, please let me know if you find any issues with it.

[art049]

Hey, thanks a lot. I'll have a look!