preload doesn't set the reverse association

[BrucePerens]

I have a URLPath model which belongs_to my Language model. Language has_one URLPath. I load both objects using URLPathQuery.new.path(path).preload_language.first
In the two resulting records, url_path.language is valid, but url_path.language.url_path is nil.

Preloading should set both sides of the association.

If I do something like this: URLPathQuery.new.path(path).preload_language.preload_url_path.first
then I get two copies of the URLPath record, and the url_path.language.url_path.language is nil.

[matthewmcgarvey]

Looked into this for a bit and I think that it would be quite difficult to accomplish. Because of it being a compiled language, ModelA needs to know which method to call on ModelB to set itself at compile time. Because it is very common to name the association something other than just the class name, ModelA would have to access ModelB::ASSOCIATIONS in a macro to determine the name of the method to call.

Maybe someone has a simpler solution?