gist_test.rb

require 'active_record'
require 'minitest/autorun'
require 'logger'
puts "ActiveRecord: #{ActiveRecord::VERSION::STRING}"

case ARGV[0]
when 'pg'
  require 'pg'
  ActiveRecord::Base.establish_connection(adapter: "postgresql", host: "localhost", user: "postgres", database: "test")
when 'mysql'
  require 'mysql2'
  ActiveRecord::Base.establish_connection(adapter: "mysql2", host: "localhost", database: "test")
else
  require 'sqlite3'
  ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
end


ActiveRecord::Base.logger = Logger.new(STDOUT)


class Round < ActiveRecord::Base
  connection.create_table table_name, force: true do |t|
  end

  has_many :cards_rounds
  has_many :cards, through: :cards_rounds
  accepts_nested_attributes_for :cards_rounds

  validate :round_validations

  private

  def round_validations
    if cards.empty? ### THIS IS CHANGED!
#    unless cards.map(&:id).uniq.size == 3
      errors.add(:round, "Must have 3 unique cards")
    end
    unless cards.map(&:quality).uniq.size == 1
      errors.add(:round, "Cards must be of the same rarity")
    end
  end
end

class CardsRound < ActiveRecord::Base
  connection.create_table table_name, force: true do |t|
    t.column :card_id, :integer
    t.column :round_id, :integer
  end
  belongs_to :card
  belongs_to :round
end

class Card < ActiveRecord::Base
  connection.create_table table_name, force: true do |t|
    t.string :value
    t.string :quality
  end
  has_many :cards_rounds
  has_many :rounds, through: :cards_rounds
end


class BugTest < MiniTest::Unit::TestCase
  def test_cards
    cards = 3.times.map { |i| Card.new(value: "foo #{i}", quality: "good") }
    round = Round.new(cards: cards)
    round.save!
    assert_equal 3, Round.last.cards.count
    assert_equal 3, Round.last.cards_rounds.count
  end
end