c# - N替代ILogger .NET Core

我正试图围绕异常处理编写单元测试，以便验证日志记录器是否正确记录了异常。我正在使用nsubstitute作为一个模拟框架，我的测试必须遵循以下步骤：

[Fact]
public void LogsExcpetionWhenErrorOccursInCreate()
{
   var newUser = new UserDataModel
   {
      FirstName = "Rick",
      MiddleName = "Jason",
      LastName = "Grimes",
      Email = "[email protected]",
      Created = new DateTime(2007, 8, 15)
   };
   var exception = new Exception("Test Exception");
   // configure InsertOne to throw a generic excpetion
   _mongoContext.InsertOne(newUser).Returns(x => { throw exception; });

   try
   {
      _collection.Create(newUser);
   }
   catch
   {
      // validate that the logger logs the exception as an error
      _logger.Received().LogError(exception.Message);
   }
}

要使用以下方法测试日志记录：

public UserDataModel Create(UserDataModel user)
{
     try
     {
          return MongoContext.InsertOne(user);
     }
     catch(Exception e)
     {
           _logger?.LogError(e.Message);
           throw new DataAccessException("An error occurred while attempting to create a user.", e);
      }

}
我的测试失败，错误如下：

Message: NSubstitute.Exceptions.ReceivedCallsException : Expected to receive a call matching:
    Log<Object>(Error, 0, Test Exception, <null>, Func<Object, Exception, String>)
Actually received no matching calls.
Received 1 non-matching call (non-matching arguments indicated with '*' characters):
    Log<Object>(Error, 0, *Test Exception*, <null>, Func<Object, Exception, String>)

我不知道为什么这是失败的，因为即使在当时的错误消息调用是相同的。
提前谢谢！
更新：
这是测试的构造函数，这是我注入logger mock的地方：

public UserCollectionTest()
{
   _mongoContext = Substitute.For<IMongoContext<UserDataModel>>();
   _logger = Substitute.For<ILogger>();
   // create UserCollection with our mock client
   _collection = new UserCollection(_mongoContext, _logger);
}

最佳答案

logerror不是一个ilogger方法，所以当您试图检查这个方法是否是用某些参数调用时，nsubstitute试图以某种方式处理它（我不知道具体如何处理），但失败了。
logerror扩展方法的代码是：

public static void LogError(this ILogger logger, string message, params object[] args)
{
  if (logger == null)
    throw new ArgumentNullException("logger");
  logger.Log<object>(LogLevel.Error, (EventId) 0, (object) new FormattedLogValues(message, args), (Exception) null, LoggerExtensions._messageFormatter);
}

所以您必须检查是否调用了日志方法。
我把你的例子简化了一点。我想这个主意应该很清楚。

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();

        var logger = Substitute.For<ILogger>();
        try
        {
            Create(logger);
        }
        catch
        {
            logger.CheckErrorMessage("My Message");
        }
    }

    public string Create(ILogger logger)
    {
        try
        {
            throw new Exception("My Message");
        }
        catch (Exception e)
        {
            logger?.LogError(e.Message);
            throw new Exception("An error occurred while attempting to create a user.", e);
        }
    }
}

public static class TestExtensions
{
    public static void CheckErrorMessage(this ILogger logger, string message)
    {
        logger.Received().Log(
            LogLevel.Error,
            Arg.Any<EventId>(),
            Arg.Is<object>(o => o.ToString() == message),
            null,
            Arg.Any<Func<object, Exception, string>>());
    }
}

logError

c# - N替代ILogger .NET Core