Fix exception when using a resource with a composite primary/foreign key association

[filipegiusti]

Fixes #3334

Fix NoMethodError: undefined method to_sym' for an instance of Array` raised by this line when an association uses a composite primary key/foreign key.

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works

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[adrianthedev]

Thanks @filipegiusti!
Would you be able to add some tests for this as well?

The approach I would take is to create a new model & resource which uses composite foreign keys and test that.

Thank you for tackling this!

[filipegiusti]

The approach I would take is to create a new model & resource which uses composite foreign keys and test that.

I searched for a test file at spec/lib/avo/fields/belongs_to_field.rb or using the search term spec fields belongs_to but I couldn't find anything. I'm not sure where such test would be and how it would look like, I don't have much experience testing libraries.

PS: I also searched for some sort of coverage tool that would help pinpoint which tests cover that method and tried to get github copilot to find such tests, all without luck.

[adrianthedev]

Can you create a new spec next to this one and test only the composite behavior?

[Paul-Bob]

@filipegiusti I can take over and create the test. Could you share some details about your environment setup? We don’t have any tables with composite primary or foreign keys, so I’m unsure how to configure the environment to test this change.

[filipegiusti]

It all started when we added the primary_key and foreign_key. We have these models.

class Profile
  has_one :membership, primary_key: %i[organization_id id], foreign_key: %i[organization_id profile_id], dependent: :destroy, inverse_of: :profile
end

class Membership
  belongs_to :profile, primary_key: %i[organization_id id], foreign_key: %i[organization_id profile_id], inverse_of: :membership
end

Both models have a primary key of id and an unique index of [organization_id, id].

The edit page of Profile works, the exception is raised when Profile is attempted to be updated.

We also have:

class Resources::Profile < Avo::BaseResource
  def fields
    field :membership, as: :belongs_to, only_on: :show
  end
end

[filipegiusti]

I might be able to look at this next week.