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c#.net-coremicrosoft-fakes

Any alternative for Microsoft Fakes in .NET Core?


I am looking for an alternative to Microsoft Fakes in .NET Core. I know it is no longer supported in .NET Core. I just do not understand why not, I think it was a good solution in certain situations.

My problem is that I want to mock DateTime.Now. Previously you could do this with the following code:

System.Fakes.ShimDateTime.NowGet = () => 
{ 
   return new DateTime(2000, 1, 1); 
};

It is described in the Microsoft documentation, see the link for more information: https://learn.microsoft.com/en-us/visualstudio/test/using-shims-to-isolate-your-application-from-other-assemblies-for-unit-testing?view=vs-2017

For now I solved it by creating a wrapper for DateTime, which looks like this:

/// <summary>
/// Used for getting DateTime.Now(), time is changeable for unit testing
/// </summary>
public static class SystemTime
{
   /// <summary> 
   /// Normally this is a pass-through to DateTime.Now, but it can be 
   /// overridden with SetDateTime( .. ) for testing or debugging.
   /// </summary>
   public static Func<DateTime> Now = () => DateTime.Now;

   /// <summary> 
   /// Set time to return when SystemTime.Now() is called.
   /// </summary>
   public static void SetDateTime(DateTime dateTimeNow)
   {
      Now = () =>  dateTimeNow;
   }

   /// <summary> 
   /// Resets SystemTime.Now() to return DateTime.Now.
   /// </summary>
   public static void ResetDateTime()
   {
       Now = () => DateTime.Now;
   }
}

I owe this solution to the next StackOverflow post: Unit Testing: DateTime.Now

But I am not satisfied with this solution yet, because I feel I have to adjust my implementation for my testing. I do not think this is desirable.

I hope someone can help me with this, thanks in advance for the effort.


Solution

  • I am looking for an alternative to Microsoft Fakes in .NET Core. I know it is no longer supported in .NET Core. I just do not understand why not, I think it was a good solution in certain situations.

    Since May 19th 2020 Microsoft Fakes supports .NET Core.

    https://learn.microsoft.com/en-us/visualstudio/releases/2019/release-notes#16.6.0