Template for https://github.com/rails/rails/pull/16698

test_association_primary_key.rb

unless File.exist?('Gemfile')
  File.write('Gemfile', <<-GEMFILE)
    source 'https://rubygems.org'
    gem 'rails', github: 'rails/rails'
    gem 'arel', github: 'rails/arel'
    gem 'rack', github: 'rack/rack'
    gem 'i18n', github: 'svenfuchs/i18n'
    gem 'sqlite3'
  GEMFILE

  system 'bundle'
end

require 'bundler'
Bundler.setup(:default)

require 'active_record'
require 'minitest/autorun'
require 'logger'

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :products, primary_key: "sku"  do |t|
    t.string :name
    t.belongs_to :stupid_supplier
  end

  create_table :versions, primary_key: "vid" do |t|
    t.belongs_to :product
  end

  create_table :stupid_suppliers, primary_key: "sid" do |t|
  end
  
end

class Product < ActiveRecord::Base
  self.primary_key = "sku"
  
  has_many :versions
  belongs_to :stupid_supplier
end

class Version < ActiveRecord::Base
  self.primary_key = "vid"

  belongs_to :product
end

class StupidSupplier < ActiveRecord::Base
  self.primary_key = "sid"

  has_one :product
end


class BugTest < Minitest::Test
  def test_association_stuff
    product = Product.create!(sku: 10)
    
    product.stupid_supplier = StupidSupplier.create!(sid: 20)
    
    product.versions.create!(vid: 30)

    assert_equal product.id, Version.first.product_id
    assert_equal product.versions.first.id, Version.first.id
    assert_equal product.stupid_supplier_id, StupidSupplier.first.id
  end
end