Compile error for optional association preloads

[akadusei]

I'm getting a compile error when preloading optional associations. It seems to originate from here:

avram/src/avram/associations/belongs_to.cr

Line 64 in 6d5357e

assoc = preload_query.id(record.{{ foreign_key }}).first?

Error: 

The 'eq' method can't compare a column to a value that may be 'nil'.
# ...

It seems the #eq method does not accept nilable arguments.

[jwoertink]

This is correct, the eq method doesn't allow for nilable arguments. You'd have to use nilable_eq in that case... but I guess the bigger question is why are you getting this error? Or... why has this not come up until now? 😂 I have a few nilable associations in my apps that get preloaded, so it would seem that either this code should work, or it should have thrown this error quite a while ago. Very strange 🤔

[matthewmcgarvey]

This bug was introduced in 285a902 which is really new and I think only affects preloading in the new way (with an existing record).

[akadusei]

You'd have to use nilable_eq in that case... but I guess the bigger question is why are you getting this error?

I got this error while testing Shield with the master branch of Avram. It's an existing code, calling BearerLoginQuery.preload_oauth_client which compiles OK with Avram v1.0.0-rc1.

This bug was introduced in 285a902 which is really new and I think only affects preloading in the new way (with an existing record).

That's correct. The said line should probably check if the association is nil and call the appropriate method.

[jwoertink]

Ah! That explains it. Yeah, I haven't tested the main branch stuff 😅 Good find.