active_record_bidirectional_accepts_nested_for_test.rb

# frozen_string_literal: true

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'

  gem 'activerecord', '6.0.3.4'
  gem 'sqlite3'
end

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

ActiveRecord::Base.establish_connection(
  adapter: 'sqlite3',
  database: ':memory:'
)
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :users, force: true

  create_table :teams, force: true

  create_table :team_memberships, force: true do |t|
    t.integer :team_id
    t.integer :user_id
    t.index %i[team_id user_id]
  end

  create_table :posts, force: true do |t|
    t.string :title, null: false
    t.integer :user_id
    t.index :user_id
  end
end

class Team < ActiveRecord::Base
  has_many :team_memberships
  has_many :users, through: :team_memberships
end

class User < ActiveRecord::Base
  has_many :team_memberships
  has_many :teams, through: :team_memberships
  has_many :posts

  accepts_nested_attributes_for :posts
end

class TeamMembership < ActiveRecord::Base
  belongs_to :team
  belongs_to :user
end

class Post < ActiveRecord::Base
  belongs_to :user

  accepts_nested_attributes_for :user
end

class BugTest < Minitest::Test
  def test_association_stuff
    team = Team.create!
    user = User.create!(
      posts: [
        Post.new(title: 'dummy title')
      ],
      team_ids: [team.id]
    )
    assert_equal 1, user.teams.count
  end
end

  1) Failure:
BugTest#test_association_stuff [-:73]:
Expected: 1
  Actual: 2

1 runs, 1 assertions, 1 failures, 0 errors, 0 skips