无法测试用ILogger<T>接收到的NSubstitute
无法测试用ILogger<T>接收到的NSubstitute
提问于 2020-03-14 15:53:45
我有一个.Net核心3应用程序，并试图用我的方法测试对ILogger的调用：
public class MyClass
{
private readonly ILogger<MyClass> _logger;
public MyClass(ILogger<MyClass> logger)
{
_logger = logger;
}
public void MyMethod(string message)
{
_logger.LogError(message);
}
}在SO和博客上找到答案之后，我知道我必须针对接口方法而不是扩展方法进行测试，所以我进行了以下测试：
[TestMethod]
public void MyMethodTest()
{
// Arrange
var logger = Substitute.For<ILogger<MyClass>>();
var myClass = new MyClass(logger);
var message = "a message";
// Act
myClass.MyMethod(message);
// Assert
logger.Received(1).Log(
LogLevel.Error,
Arg.Any<EventId>(),
Arg.Is<object>(o => o.ToString() == message),
null,
Arg.Any<Func<object, Exception, string>>());
}但是，这是不起作用的，我得到了这个错误：
Test method MyLibrary.Tests.MyClassTests.MyMethodTest threw exception:
NSubstitute.Exceptions.ReceivedCallsException: Expected to receive exactly 1 call matching:
Log<Object>(Error, any EventId, o => (o.ToString() == value(MyLibrary.Tests.MyClassTests+<>c__DisplayClass0_0).message), <null>, any Func<Object, Exception, String>)
Actually received no matching calls.
at NSubstitute.Core.ReceivedCallsExceptionThrower.Throw(ICallSpecification callSpecification, IEnumerable`1 matchingCalls, IEnumerable`1 nonMatchingCalls, Quantity requiredQuantity)
at NSubstitute.Routing.Handlers.CheckReceivedCallsHandler.Handle(ICall call)
at NSubstitute.Routing.Route.Handle(ICall call)
at NSubstitute.Core.CallRouter.Route(ICall call)
at NSubstitute.Proxies.CastleDynamicProxy.CastleForwardingInterceptor.Intercept(IInvocation invocation)
at Castle.DynamicProxy.AbstractInvocation.Proceed()
at NSubstitute.Proxies.CastleDynamicProxy.ProxyIdInterceptor.Intercept(IInvocation invocation)
at Castle.DynamicProxy.AbstractInvocation.Proceed()
at Castle.Proxies.ObjectProxy.Log[TState](LogLevel logLevel, EventId eventId, TState state, Exception exception, Func`3 formatter)
at MyLibrary.Tests.MyClassTests.MyMethodTest() in D:\Source\Scratch\MyLibrary\MyLibrary.Tests\MyClassTests.cs:line 25我做错了什么？
netcoreapp3.0 / Microsoft.Extensions.Logging 3.1.2 / NSubstitute 4.2.1
更新：--我尝试了与Arg.Any<>()的匹配，并得到了相同的结果：
logger.Received(1).Log(
Arg.Any<LogLevel>(),
Arg.Any<EventId>(),
Arg.Any<object>(),
Arg.Any<Exception>(),
Arg.Any<Func<object, Exception, string>>());更新2: --我使用进行了相同的测试，得到了相同的结果：
logger.Verify(l => l.Log(
LogLevel.Error,
It.IsAny<EventId>(),
It.Is<object>(o => o.ToString() == message),
null,
It.IsAny<Func<object, Exception, string>>()),
Times.Once);结果：
Test method MyLibrary.Tests.Moq.MyClassTests.MyMethodTest threw exception:
Moq.MockException:
Expected invocation on the mock once, but was 0 times: l => l.Log<object>(LogLevel.Error, It.IsAny<EventId>(), It.Is<object>(o => o.ToString() == "a message"), null, It.IsAny<Func<object, Exception, string>>())
Performed invocations:
Mock<ILogger<MyClass>:1> (l):
ILogger.Log<FormattedLogValues>(LogLevel.Error, 0, a message, null, Func<FormattedLogValues, Exception, string>)
at Moq.Mock.Verify(Mock mock, LambdaExpression expression, Times times, String failMessage)
at Moq.Mock`1.Verify(Expression`1 expression, Times times)
at Moq.Mock`1.Verify(Expression`1 expression, Func`1 times)
at MyLibrary.Tests.Moq.MyClassTests.MyMethodTest() in D:\Source\Scratch\MyLibrary\MyLibrary.Tests.Moq\MyClassTests.cs:line 25回答 2
Stack Overflow用户
回答已采纳
发布于 2020-03-16 12:37:36
用ILogger核心3.*测试.NET调用的主要问题是，FormattedLogValues被更改为内部，这会使事情复杂化。
Moq的解决方法是使用It.IsAnyType
public class TestsUsingMoq
{
[Test]
public void MyMethod_String_LogsError()
{
// Arrange
var logger = Mock.Of<ILogger<MyClass>>();
var myClass = new MyClass(logger);
var message = "a message";
// Act
myClass.MyMethod(message);
//Assert
Mock.Get(logger)
.Verify(l => l.Log(LogLevel.Error,
It.IsAny<EventId>(),
It.Is<It.IsAnyType>((o, t) => ((IReadOnlyList<KeyValuePair<string, object>>) o).Last().Value.ToString().Equals(message)),
It.IsAny<Exception>(),
(Func<It.IsAnyType, Exception, string>) It.IsAny<object>()),
Times.Once);
}
}据我所知，NSubstitute目前还没有It.IsAnyType等效值，这在尝试使用Received方法时会出现问题。但是，有一个解决办法，因为它确实提供了一个ReceivedCalls方法，您可以迭代该方法并进行自己的调用检查。
public class TestsUsingNSubstitute
{
[Test]
public void MyMethod_String_LogsError()
{
// Arrange
var logger = Substitute.For<ILogger<MyClass>>();
var myClass = new MyClass(logger);
var message = "a message";
// Act
myClass.MyMethod(message);
//Assert
Assert.That(logger.ReceivedCalls()
.Select(call => call.GetArguments())
.Count(callArguments => ((LogLevel) callArguments[0]).Equals(LogLevel.Error) &&
((IReadOnlyList<KeyValuePair<string, object>>) callArguments[2]).Last().Value.ToString().Equals(message)),
Is.EqualTo(1));
}
}作为一种解决方法，它还不错，可以很容易地打包到扩展方法中。
FormattedLogValues实现了IReadOnlyList<KeyValuePair<string, object>>。此列表中的最后一项是您指定的原始消息。
Stack Overflow用户
发布于 2022-04-08 10:31:14
我尝试将Logger封装在适配器上，更像是一个代理类。您可以模拟适配器接口，这将返回调用了什么日志函数。
public class LoggerAdapter<TType> : ILoggerAdapter<TType>
{
private readonly ILogger<TType> _logger;
public LoggerAdapter(ILogger<TType> logger)
{
_logger = logger;
}
public void LogInformation(string message, params object[] args)
{
_logger.LogInformation(message,args);
}
public void LogError(string message, params object[] args)
{
_logger.LogError(message, args);
}
} private readonly ILoggerAdapter<PosUpdateService> _logger = Substitute.For<ILoggerAdapter<PosUpdateService>>();_logger.Received(1).LogInformation("User with Id {id} was fetched in {0} milliseconds",
Arg.Is(Id),
Arg.Any<long>());页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/60684578
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