rails/rails#23739

info.md

Related Issues:

• rails/rails#16449
• rails/rails#18988
• rails/rails#19550
• rails/rails#22602
• rails/rails#23265
• rails/rails#23615

Related PRs:

• rails/rails#23357

Tests Status:

	4.1.14.1	4.2.5.1	master
assign	1 👍	2 👎	1 👍
assign + reload	2 👎	1 👍	1 👍
clear by re-assign	0 👍	3 👎	1 👎
clear by re-assign + reload	1 👎	1 👎	1 👎
clear by destroy_all	0 👍	2 👎	0 👍
clear by destroy_all + reload	0 👍	0 👍	0 👍
failed	2	4	2

implicit counter cache (cache column, but no counter_cache on belongs_to):

	4.1.14.1	4.2.5.1	master
assign	1 👍	1 👍	1 👍
assign + reload	1 👍	1 👍	1 👍
clear by re-assign	0 👍	2 👎	1 👎
clear by re-assign + reload	0 👍	1 👎	1 👎
clear by destroy_all	0 👍	1 👎	0 👍
clear by destroy_all + reload	0 👍	1 👎	0 👍
failed	0	4	2

tests.rb

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