Decoding BSON values

[davidbayo10]

Hello,

I would like to know if decoding bson values from MongoDB could be a feature of this amazing lib.

type User struct {
	Name  mo.Option[string] `bson:"name"`
}

error decoding key name: cannot decode string into a mo.Option[string]

I would to suggest to decode an empty string or none present key to None.

Thank you in advance.

[samber]

Hi @davidbayo10

Sure. I suppose implementing BSON marshalers must be simple. Feel free to propose a PR.

I just checked the bson library from MongoDB driver. It seems the provide a codec registry:
https://pkg.go.dev/go.mongodb.org/mongo-driver/bson/bsoncodec

I think we should create a sub-package under github.com/samber/mo/bson in order to not embed go.mongodb.org/mongo-driver into global go.mod and keep it lightweight. That package would later be imported using import _ "github.com/samber/mo/bson". WDYT ?

[paulhobbel]

Any progression on this? If not I think I can work on an implementation since we need it as well

[samber]

please do!

[paulhobbel]

Okay so I don't fully understand how we could add support by doing this in a bson package. The v2 of the mongo-driver removed access to the global registry so you can't register encoders/decoders globally. This means one would have to create their own registry and then tell all the parts of the code where they marshal/unmarshal to use the custom registry.

How big of a problem would it be if we added the UnmarshalBSON/MarshalBSON to the main package?

[samber]

Yes, i think this is the way to go.

We already added some marshal/unmarshall methods.