test_case_active_record_has_many_through_counter_cache_bugs.rb

begin
  require 'bundler/inline'
rescue LoadError => e
  $stderr.puts 'Bundler version 1.10 or later is required. Please update your Bundler'
  raise e
end

gemfile(true) do
  source 'https://rubygems.org'
  # gem 'activerecord', '5.0.0.beta2'
  # gem 'activerecord', '4.2.5.1'
  # gem 'activerecord', '4.2.0'
  # gem 'activerecord', '4.1.14.1'
  # gem 'activerecord', '4.1.2'
  # gem 'activerecord', github: 'piotrj/rails', branch: 'issue_23265'
  gem 'activerecord', github: 'rails/rails'
  gem 'sqlite3'
end

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

# Ensure backward compatibility with Minitest 4
# Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

# 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, force: true do |t|
  end

  create_table :classifications, force: true do |t|
    t.integer :product_id
    t.integer :taxon_id
  end

  create_table :taxons, force: true do |t|
    t.integer :products_count, default: 0
  end
end

class Product < ActiveRecord::Base
  has_many :classifications
  has_many :taxons, through: :classifications
end

class Classification < ActiveRecord::Base
  belongs_to :product
  belongs_to :taxon, counter_cache: :products_count
end

class Taxon < ActiveRecord::Base
  has_many :classifications
  has_many :products, through: :classifications
end

class BugTest < Minitest::Test

  def taxon
    @taxon ||= Taxon.create!
  end

  def product
    @product ||= Product.create!
  end

  def test_counter_cache_initial_value
    assert_equal 0, taxon.products_count
  end

  def test_counter_cache_after_assign
    taxon.products = [product]
    assert_equal 1, taxon.products_count
  end

  def test_counter_cache_after_assign_and_reload
    taxon.products = [product]
    assert_equal 1, taxon.reload.products_count
  end

  def test_counter_cache_after_clear_by_assign
    taxon.products = [product]
    taxon.products = []
    assert_equal 0, taxon.products_count
  end

  def test_counter_cache_after_clear_by_assign_and_reload
    taxon.products = [product]
    taxon.products = []
    assert_equal 0, taxon.reload.products_count
  end

  def test_counter_cache_after_clear_by_destroy_all
    taxon.products = [product]
    taxon.products.destroy_all
    assert_equal 0, taxon.products_count
  end

  def test_counter_cache_after_clear_by_destroy_all_and_reload
    taxon.products = [product]
    taxon.products.destroy_all
    assert_equal 0, taxon.reload.products_count
  end

end