Rails - composite primary key as foreign key - relationship not working

I have a problem with models with composite primary key. Look at my code

Migration

class CreateDataSets < ActiveRecord::Migration
  def change
    create_table :data_sets do |t|
      t.integer :synchronization_report_id, null: true
      t.string :configuration_id,            null:false, limit: 100
      t.datetime :synch_time,               null: false

      t.timestamps null: false
    end

    execute "ALTER TABLE data_sets DROP CONSTRAINT data_sets_pkey;"
    execute "ALTER TABLE data_sets ADD CONSTRAINT data_sets_pkey PRIMARY KEY (id, synchronization_report_id);"
    execute "ALTER TABLE data_sets ADD FOREIGN KEY (synchronization_report_id) REFERENCES synchronization_reports (id);"
  end
end

class CreateDataAreas < ActiveRecord::Migration
  def change
    create_table :data_areas do |t|
      t.string :configuration_id,           null: false, limit: 100

      t.integer :data_set_id,               null: true
      t.integer :synchronization_report_id, null: true

      t.string :status,                     null: false, limit: 20
      t.string :error_type,                 null: true, limit: 100
      t.string :error_text,                 null: true
      t.string :sql,                        null: true
      t.integer :records_files_processed,   null: false

      t.timestamps null: false
    end

    execute "ALTER TABLE data_areas DROP CONSTRAINT data_areas_pkey;"
    execute "ALTER TABLE data_areas ADD CONSTRAINT data_areas_pkey PRIMARY KEY (id, data_set_id, synchronization_report_id);"
    execute "ALTER TABLE data_areas ADD FOREIGN KEY (data_set_id, synchronization_report_id) REFERENCES data_sets(id, synchronization_report_id);"
  end
end

      

        
        
        
      

    

My Models

class SynchronizationReport::DataSet < ActiveRecord::Base
  self.table_name = :data_sets
  self.primary_keys = :id, :synchronization_report_id
  belongs_to :synchronization_report
  has_many :data_areas, class_name: SynchronizationReport::DataArea, dependent: :delete_all
  validates_presence_of :synchronization_report_id, :configuration_id, :synch_time
  validates_length_of :configuration_id, in: 2..100
end

class SynchronizationReport::DataArea < ActiveRecord::Base
  self.table_name = :data_areas
  self.primary_keys = :id, :data_set_id, :synchronization_report_id
  belongs_to :data_set, foreign_key: [:data_set_id, :synchronization_report_id]
  belongs_to :synchronization_report
  validates_inclusion_of :status, in: %w[imported import_failed exported export_failed]
  validates_presence_of :configuration_id, :data_set_id, :synchronization_report_id, :status, :records_files_processed
  validates_length_of :configuration_id, in: 3..100
  validates_length_of :status, in: 3..20
  validates_length_of :error_type, in: 3..100, allow_nil: true
end

      

        
        
        
      

    

The problem is that I cannot use the data_areas relation.

I cannot pass this test.

RSpec.describe SynchronizationReport::DataSet, type: :model do
  describe "data_areas relation" do
    before(:all) do
      (0...5).each do |i|
        FactoryGirl.create(:data_area, data_set_id: @data_set.id[0][1], synchronization_report_id: @data_set.synchronization_report.id)
      end
    end

    it { should have_many(:data_areas) }
    it { expect( @data_set.data_areas.size ).to eq 5 }
  end
end

      

        
        
        
      

    

One last statement when I check for relationship failure.

 Failure/Error: it { expect( @data_set.data_areas.size ).to eq 5 }

   expected: 5
        got: 0

      

        
        
        
      

    

What am I doing wrong? I have read all threads with similar questions on SO, but it didn't work for me.

To help you understand my problem, I created a simple app with this same problem

https://github.com/Draqun/composite_primary_keys_as_foreign_key_example

There is a test in the spec that needs to be passed.