.NET Core 中 Microsoft Fakes 的任何替代方案？

Question

我正在寻找 .NET Core 中 Microsoft Fakes 的替代品。我知道 .NET Core 不再支持它。我只是不明白为什么不，我认为在某些情况下这是一个很好的解决方案。

我的问题是我想模拟 DateTime.Now。以前您可以使用以下代码执行此操作：

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

在微软文档中有描述，详见link：https://docs.microsoft.com/en-us/visualstudio/test/using-shims-to-isolate-your-application-from-other-assemblies-for-unit-testing?view=vs-2017

现在我通过为 DateTime 创建一个包装器解决了这个问题，它看起来像这样：

/// <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;
   }
}

这个解决方案归功于下一个 Whosebug post： Unit Testing: DateTime.Now

但我对这个解决方案还不满意，因为我觉得我必须为我的测试调整我的实现。我认为这是不可取的。

我希望有人能帮我解决这个问题，在此先感谢您的努力。

Answer 1

感谢所有评论，这对我很有帮助。我稍微修改了我的实现；

SystemTime class 现在称为 DateTimeProvider，如下所示：

/// <summary>
/// Used for getting DateTime.Now(), time is changeable for unit testing
/// </summary>
public class DateTimeProvider : IDateTimeProvider
{
   /// <summary> 
   /// Normally this is a pass-through to DateTime.Now, but it can be 
   /// overridden with SetDateTime( .. ) for testing or debugging.
   /// </summary>
   private Func<DateTime> _now = () => DateTime.Now;
   public Func<DateTime> Now { get => _now; private set => _now = value; }

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

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

我选择将 setter 设为 Now() 的私有。因此，开发人员必须显式使用 SetDateTime() 方法来更改时间。您还可以选择使用自动 getter 和 setter 属性.

我还添加了一个接口，以便 class 可以被注入：

public interface IDateTimeProvider
{
    Func<DateTime> Now { get; }
    void SetDateTime(DateTime dateTimeNow);
    void ResetDateTime();
}

我希望其他人也能从中受益。

Answer 2

Pose 对此效果很好。

using Pose;

Shim dateTimeShim = Shim.Replace(() => DateTime.Now).With(() => new DateTime(2004, 4, 4));

// This block executes immediately
PoseContext.Isolate(() =>
{
    // All code that executes within this block
    // is isolated and shimmed methods are replaced

    // Outputs "4/4/04 12:00:00 AM"
    Console.WriteLine(DateTime.Now);

}, dateTimeShim);

Answer 3

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.

自 2020 年 5 月 19 日起 Microsoft Fakes 支持 .NET Core。

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

.NET Core 中 Microsoft Fakes 的任何替代方案？

Any alternative for Microsoft Fakes in .NET Core?

c#

microsoft-fakes

.net-core