rails 的测试的 bug 当你的 model 的 after_create 中有raise 时

app/models/part.rb

class Part < ActiveRecord::Base
  def after_create
    raise "no way" if self.name == "test"
  end
end

app/controllers/parts_controller.rb

class PartsController < ApplicationController
  def test
    Part.create!(:name => "test")
  end
end

test/functional/parts_controller_test.rb

require File.dirname(__FILE__) + '/../test_helper'

class PartsControllerTest < ActionController::TestCase
  def test_test
    old_count = Part.count
    post :test rescue nil   
    assert_equal(old_count, Part.count)
  end
end

    ruby test\functional\parts_controller_test.rb

结果是

<2> expected but was
<3>.

日志是

Processing PartsController#test (for 0.0.0.0 at 2008-05-01 16:26:57) [POST]
  Session ID: 
  Parameters: {"action"=>"test", "controller"=>"parts"}
  Part Create (0.000000)   INSERT INTO parts ("name", "updated_at", "created_at") VALUES('test', '2008-05-01 16:26:57', '2008-05-01 16:26:57')
  SQL (0.000000)   SELECT count(*) AS count_all FROM parts 

看到没. 居然没有 回滚

换用集成测试
test/integration/model_hg_test.rb

require "#{File.dirname(__FILE__)}/../test_helper"

class ModelHgTest < ActionController::IntegrationTest
  fixtures :parts

  def test_truth
    old_count = Part.count
    
    puts Part.find_by_sql("select * from parts").collect(&:id).join(", ")
    puts Part.find_by_sql("select * from parts").collect(&:name).join(", ")
    
    post '/parts/test'
    
    puts Part.find_by_sql("select * from parts").collect(&:id).join(", ")
    puts Part.find_by_sql("select * from parts").collect(&:name).join(", ")
    
    assert_equal(old_count, Part.count)
    
  end
end

结果是

D:\t1\t1>ruby test\integration\model_hg_test.rb
Loaded suite test/integration/model_hg_test
Started
953125641, 996332877
MyString, MyString
953125641, 996332877, 996332878
MyString, MyString, test
F
Finished in 1.281 seconds.

  1) Failure:
test_truth(ModelHgTest)
    [test/integration/model_hg_test.rb:17:in `test_truth'
     E:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/integration.rb:547:in `
']:
<2> expected but was
<3>.

1 tests, 1 assertions, 1 failures, 0 errors

没有 回滚

狂汗!!!

如果在create后raise异常回滚,会让我无法理解
检查数据最好的时机应该是
# (1) before_validation
# (2) before_validation_on_create
# (-) validate
# (-) validate_on_create

这个需求很普遍

比如一个是零件表, 另一个是零件的创建日志表

比如 修改记录 等等..

写到 after_create 比用事务代码看起来要好看和自然很多.

另外. 奇怪的是, 在 development 和 production 下, 都有回滚

只有 test 下没有回滚, 这个看似 Rails 测试的 BUG

我在官方论坛搜索一下, 没有搜到

干嘛不放在before_save呢？

检查test环境的db以及对应的table是否和dev/production下一致.比如,store engine是否一致.
举个例子,如果dev和production用的是mysql,table是innodb,而test用了myisam,就有可能出现你这样的问题.
最好给出你的环境配置,不然大家只能猜.

默认配置

# SQLite version 3.x
#   gem install sqlite3-ruby (not necessary on OS X Leopard)
development:
  adapter: sqlite3
  database: db/development.sqlite3
  timeout: 5000

# Warning: The database defined as 'test' will be erased and
# re-generated from your development database when you run 'rake'.
# Do not set this db to the same as development or production.
test:
  adapter: sqlite3
  database: db/test.sqlite3
  timeout: 5000

production:
  adapter: sqlite3
  database: db/production.sqlite3
  timeout: 5000

例如Part
在 before_save 前会有很多的验证. 都可以导致创建失败.

这个场景正好要做,创建成功后记录创建日志的问题

所以用 after_save 在我的场景内更合适.


撇开 用 after_save 还是 before_save 或是 xx_validation 等等.
为什么, Rails 的测试环境 要不回滚呢?
是BUG 还是故意为之, 待有空时看看源码才行啦

还有一个可能造成这个问题的原因是rails test的transactional fixture功能.

缺省是打开的,会造成transaction的嵌套,导致rollback延迟, 在test method中不能执行.

你可以试试在test_helper中把它关掉:

  self.use_transactional_fixtures = false

需要注意,改变这个选项可能会影响一些依赖这个功能的测试.