小编Pet*_*ter的帖子

我有一个测试,我向一个拥有一个帐户的用户付款.该帐户包含余额并具有许多交易.

付款完成后,将创建一个交易并更新帐户余额.

使用assert_difference检查事务数量更改会给出预期结果.但是,使用assert_difference检查余额是否已更改.我可以看到SQL更新我的日志中的余额,但断言认为它没有改变.

我完全糊涂了,有人可以解释一下吗？

提前致谢.

这通过:

assert_difference("a_user.account.transactions.count", 1) do
  # Process payment
end

这失败了,说没有变化:

assert_difference("a_user.account.balance", 250.00) do
  # Process payment
end

这是断言的失败消息:

"a_user.account.balance" didn't change by 250.0.
<300.0> expected but was
<50.0>.

这是日志文件中的相关SQL:

  User Load (0.4ms)   SELECT * FROM `users` WHERE (`users`.`id` = 108093344) 
  Account Load (0.2ms)   SELECT * FROM `accounts` WHERE (`accounts`.user_id = 108093344) LIMIT 1
  Transaction Columns (1.5ms)   SHOW FIELDS FROM `transactions`
  Transaction Create (0.3ms)   INSERT INTO `transactions` (`created_at`, `updated_at`, `amount`, `account_id`, `detail`) VALUES('2011-02-01 17:15:21', '2011-02-01 17:15:21', 250.0, …