00_buy_weapon_test.rb

class BuyWeaponTest < ActiveSupport::TestCase
  test "User buys a weapon" do
    mp5      = WeaponType.create('mp5', gold: 40)
    ak47     = WeaponType.create('ak47', gold: 100)
    argo     = User.create(name: 'Argo', gold: 100)
    argo_mp5 = Weapon.create(weapon_type: mp5, user: argo)

    UserBuysWeapon.new(user, ak47).perform!

    assert_equal ak47, argo.weapon.weapon_type, "User's new weapon should be a AK-47"
    assert_equal 20, argo.gold, 'User should be granted 50% of his current MP5'
  end
end