GeoJSON object no longer receives a default type

[Jeffrey-Vervoort-KNMI]

After upgrading from 0.4.3 to 0.6.2 the validation raises an exception for type in FeatureCollection, Feature and Point, in our code but also for the Usage example in the readme.md.

At version 0.4.3 GeoJSON objects received a default see below:

class FeatureCollection(GenericModel, Generic[Geom, Props], GeoInterfaceMixin):
    """FeatureCollection Model"""
    type: str = Field("FeatureCollection", const=True)

The type field changed in 0.6.0 to a Literal and the default is removed:

class FeatureCollection(GenericModel, Generic[Geom, Props], GeoInterfaceMixin):
    """FeatureCollection Model"""
    type: Literal["FeatureCollection"]

When I read the spec: A GeoJSON object has a member with the name "type". The value of the member MUST be one of the GeoJSON types., I think that it should receive a default. If that would be the case then it could be changed to:

class FeatureCollection(GenericModel, Generic[Geom, Props], GeoInterfaceMixin):
    """FeatureCollection Model"""
    type: Literal["FeatureCollection"] = "FeatureCollection"

If this would be an issue, then it would be necessary to also change it for the other types: Feature and Point as well.

[vincentsarago]

Hi @Jeffrey-Vervoort-KNMI
Sorry for the frustration, we changed this knowing it will be quite a breaking change but we also wanted to make sure the library was following the specification to the letter. (https://github.com/developmentseed/geojson-pydantic/blob/main/CHANGELOG.md#060a0---2023-04-04)

ref: #92 (comment)

a Feature, FeatureCollection and Geometry dictionary should have a type. If not we cannot discriminate between them. We do think that this make the library more robust but we also understand that this was a big breaking change

also already discussed in #124

Thanks for pointing out the error in the Readme, It will be fixed