Ability to call a model's class methods on the model's CollectionProxy

[frewsxcv]

Describe the bug:

Rails has the ability to call class methods on a model's CollectionProxy. See this SO for an example:

https://stackoverflow.com/questions/22304809/rails-ability-to-call-my-class-method-on-an-array

This behavior is not currently supported in sorbet-rails

Steps to reproduce:

N/A

Expected behavior:

It should typecheck

Versions:

• Ruby: ruby 2.6.3p62 (2019-04-16 revision 67580) [x86_64-darwin18]
• Rails: Rails 5.2.3
• Sorbet: Sorbet typechecker 0.4.4507 git d12b7144d2222398e0f28a772b7759fe26b2b9ba built on 2019-07-25 20:18:14 GMT with debug symbols
• Sorbet-Rails: 0.4.0

[jaredbeck]

Reproduced by sample app

Here is a sample app that reproduces this issue with the latest versions of all gems. (currently sorbet-rails 0.5.0)

https://github.com/jaredbeck/srb_ar_proxy

Highlights

Model

# typed: true
class Task < ApplicationRecord
  def self.outstanding
    where 'due < ?', Time.current
  end
end

Call Site

# typed: true

# run me with bin/rails runner bin/outstanding.rb

puts Task.all.outstanding.count

tc Output

bin/srb tc
bin/outstanding.rb:5: Method outstanding does not exist on Task::ActiveRecord_Relation https://srb.help/7003
     5 |puts Task.all.outstanding.count
             ^^^^^^^^^^^^^^^^^^^^
    sorbet/rails-rbi/models/task.rbi:128: Did you mean: Task::ModelRelationShared#extending?
     128 |  def extending(*args, &block); end
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Errors: 1

[hdoan741]

Thanks for flagging. I think it’ll be a difficult problem to solve. Rails dynamically routes missing methods from CollectionProxy to a Rails Model (another class). All user-defined class methods in a rails model is available in CollectionProxy. We can detect the method but it’ll likely be difficult to generate the method _and_ the signature correctly. I don’t know if sorbet provide any way to inflect signature for a method.

…

On Thu, Aug 15, 2019 at 12:16 PM Jared Beck ***@***.***> wrote: Reproduced by sample app Here is a sample app that reproduces this issue with the latest versions of all gems. (currently sorbet-rails 0.5.0) https://github.com/jaredbeck/srb_ar_proxy Highlights Model # typed: trueclass Task < ApplicationRecord def self.outstanding where 'due < ?', Time.current endend Call Site # typed: true # run me with bin/rails runner bin/outstanding.rb puts Task.all.outstanding.count tc Output bin/srb tc bin/outstanding.rb:5: Method outstanding does not exist on Task::ActiveRecord_Relation https://srb.help/7003 5 |puts Task.all.outstanding.count ^^^^^^^^^^^^^^^^^^^^ sorbet/rails-rbi/models/task.rbi:128: Did you mean: Task::ModelRelationShared#extending? 128 | def extending(*args, &block); end ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Errors: 1 — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#104?email_source=notifications&email_token=AAFH4AK7RPHGAGZZTKLHMNTQEWTRNA5CNFSM4IIHAS52YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD4MXODI#issuecomment-521762573>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAFH4AP7XZYMWSENGSPTUUTQEWTRNANCNFSM4IIHAS5Q> .

[hdoan741]

Jared: For the example you gave, you can turn it into a scope easily. Scopes are detected automatically by Sorbet-rails.

…

On Thu, Aug 15, 2019 at 12:31 PM Al Snow ***@***.***> wrote: How does bin/outstnding.rb normally work (without sorbet)? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#104?email_source=notifications&email_token=AAFH4ANAHK3L4JW64LYDI7LQEWVJXA5CNFSM4IIHAS52YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD4MYUCI#issuecomment-521767433>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAFH4ANFYORUFNRTDZDSOBDQEWVJXANCNFSM4IIHAS5Q> .

[hdoan741]

I'll close this for now because I don't think it's possible.

[jaredbeck]

I'll close this for now because I don't think it's possible.

OK, thanks for looking into it.

#133 documents this as a known issue.