是否可以在ExUnit测试中存根（模拟？）Ecto.UUID.generate？(Is it possible to stub(mock?) Ecto.UUID.generate in an ExUnit test?)

 工作大部分时间和失败有时看起来像一个竞争条件。 Andrew Whitechapel撰写了与RequestComAddInAutomationService 1相关的竞争条件： 
 
 
 
 COMAddIns比赛条件 
 
 
 虽然他说竞争条件不应该是进程内VBA宏的问题，但问题可能发生在您的特定场景中。 
 
 尝试建议的解决方法并循环，直到您的Addin.Object有效（C＃代码，类似于VBA）： 
 
while (utils == null)
{
    utils = (ComServiceOleMarshal.IAddinUtilities)addin.Object;
    System.Threading.Thread.Sleep(100);
}    
utils.DoSomething();
 
 1关于你正在做的事情，他的博客上有很多有用的信息，所以千万不要错过相关的文章。 

Turned out that Excel disabled the COM add-in. This is known to sometimes happen silently, without Excel complaining about anything.
 
So, since the add-in was registered with excel, the following line succeeded:
 
Set addin = Application.COMAddIns("My AddIn")
 
But since it was disabled, the object was not created and
 
Set automationObject = addin.Object
 
resulted in Nothing.