感谢 Angus Salkeld 春风化雨般的教导，此次 patch 让我更加认知测试的重要性。

   

近期稍闲，于是在 Heat 项目找了个名为 Cannot delete the stack after replacing image during stack-update Edit 的 bug 来 fix。本文并不是介绍如何 fix bug，而是感谢社区大神们春风化雨的教导和赞美社区互助的品质。首先介绍该 bug，其描述如下:

Steps to Reproduce:
    * create a stack with with a single server (see attached example template)
    * update the stack and replace the image the instance is using
        - This will fail with the error "Conflict: Port <uuid> is still in
          use. (HTTP 409) "
    * Try to delete the stack
        - This will fail with the error "Failed to DELETE :
          Error deleting backup resources:
          Resource DELETE failed:
          Forbidden: You are not authorized to perform the requested action,
          dentity:delete_user. (HTTP 403)"

折腾不久找出原因，简单的说就是 stack.stack_user_project_id 参数未被赋值，于是简单暴力的直接赋值，由于对 mox/mock 掌握不深，故没有编写单元测试，第一个 patch 共 5 行代码，review 结果可想而知。

patch1

从上图可知：

  • Jason Dunsmore 要求 patch 必须有测试用例
  • Steve Baker 细心的教我如何编写测试用例
  • Angus Salkeld 考虑更为全面，于是他把 patch 邮件给我，如下图。

patch2

粗心的我直接提交 Angus Salkeld 给的 patch，踩了他特意埋的坑后(主要在注释)，羞愧的难以自容，立刻学习 mox/mock 的用法。

patch3

之后根据 Angus Salkeld 的建议再次提交 patch，他又鼓励我添加一个用例，覆盖另一种场景。

nearly there, i had the focus of testing on the delete, but it seems it is
on the update-replacement of the server. Let's make that more explicit in
the functional test, otherwise it's going to be confusing what this test is
really doing.

patch4

Angus Salkeld 是 Heat 的 PTL，他愿如此不愿其烦的教导一个小菜鸟，令我感触颇深。