Rethink forwarding pattern from MongoCollection to MongoDatabase to Mongo #34
Description
If you see in current master, there are at least 8 cases of this pattern:
MongoCollection>>
commandInsert: newDictionary writeConcern: aConcern
"Insert using Mongo command. Answer the output of the command.
See more on https://docs.mongodb.com/manual/reference/command/insert/"
^database commandInsert: newDictionary collection: name writeConcern: aConcern
where the API of MongoCollection correctly exposes a behavior of a collection in mongodb, and always the implementations is just "forwarding" (may be not the correct word) the message to the MongoDatabase adding some parameter.
Another example, extended:
MongoCollection>>
insert: aCollection
database insert: aCollection collection: name
MongoDatabase>>
insert: aCollection collection: aString
root insert: aCollection collection: name , '.' , aString
as you can see, the MongoDatabase also forwards the message to root (an instance of Mongo).
This is not only a pattern that means annoying code... IMHO, the fact that a database contains collections doesn't imply that MongoDatabase should be a kind of facade or mediator between MongoCollection and Mongo. I think MongoCollection could send messages directly yo Mongo.
Also, MongoDatabase and MongoCollection belong to a same abstraction level. Only Mongo is more low-level stuff because it reads and writes to the socket that connects to mongodb.
Finally, a proposal to fix it: let MongoCollection know the root (Mongo instance) and not only the MongoDatabase. This:
MongoCollection>>
insert: aCollection
root insert: aCollection collection: self database name , '.' , self name