我一直在处理一组故障，其中启用VCR的测试会在我的Projects表中添加一条额外的记录，并且该记录会在其他测试中持续存在，从而导致失败，而不是在结束时回滚考试。具体来说，我有4个由我的Rails灯具创建的项目，然后是一个包含VCR卡带的测试，以添加一个额外的项目。该测试总是通过，但数据库之后不会重置为4个项目。
方便的是，该项目是开源的，因此您可以自己运行它。可以在https://github.com/linuxfoundation/cii-best-practices-badge的master上看到该错误（checkout commit 048776f，以便不获得临时解决方法）。导致问题的测试是https://github.com/linuxfoundation/cii-best-practices-badge/blob/master/test/features/github_login_test.rb（使用VCR磁带）登录到Github并从测试用户获取公共项目列表。它通过https://github.com/blowmage/minitest-rails-capybara gem使用Capybara。
使用SEED=41779 rake test运行时，使用VCR的测试会成功，但稍后的测试会失败，因为它会计算5个而不是4个项目。
以下是测试日志，您可以看到最后调用了ROLLBACK，但在测试开始时从未指定过SAVEPOINT。
---------------------------------------------------
GithubLoginTest: test_0001_Has link to GitHub Login
---------------------------------------------------
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----------------------------------------------
将此与通常设置SAVEPOINT和ROLLBACK的后续测试进行对比：
--------------------------------------------------------
ProjectStatTest: test_project_stat_matches_expect_values
--------------------------------------------------------
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--------------------------------------------
如何设置SAVEPOINT以使ROLLBACK成功？我怀疑我遇到了VCR的错误（我在https://github.com/vcr/vcr/issues/586提交了），但很难确定。
答案 0 :(得分：0)
从快速浏览一下，看起来您正在使用标记为js：true的测试进行事务测试 - 这不起作用，因为当使用支持JS Capybara的驱动程序加载正在单独线程中测试的应用程序时。然后每个线程（测试和应用程序）都有自己的数据库连接，并且在一个线程中启动的事务对另一个线程是不可见的，直到它被提交（由于事务测试可能永远不会发生） ）。这也意味着在应用程序中创建的记录不会被清理，因为它们实际上并未在回滚的测试事务中创建。您可能希望查看类似DatabaseCleaner的内容，以便与您的js：true标记测试一起使用 - https://github.com/DatabaseCleaner/database_cleaner#minitest-example和https://github.com/DatabaseCleaner/database_cleaner#rspec-with-capybara-example的混合是一个很好的起点