这是我的控制器:
public class BlogController : Controller
{
private IDAO<Blog> _blogDAO;
private readonly ILogger<BlogController> _logger;
public BlogController(ILogger<BlogController> logger, IDAO<Blog> blogDAO)
{
this._blogDAO = blogDAO;
this._logger = logger;
}
public IActionResult Index()
{
var blogs = this._blogDAO.GetMany();
this._logger.LogInformation("Index page say hello", new object[0]);
return View(blogs);
}
}
正如你所看到的，我有两个依赖项，一个IDAO和一个ILogger
这是我的测试类，我使用xUnit来测试和Moq来创建模拟和存根，我可以很容易地模拟DAO，但使用ILogger，我不知道该做什么，所以我只是传递null并注释掉运行测试时登录控制器的调用。是否有一种方法可以测试，但仍然以某种方式保存日志?
public class BlogControllerTest
{
[Fact]
public void Index_ReturnAViewResult_WithAListOfBlog()
{
var mockRepo = new Mock<IDAO<Blog>>();
mockRepo.Setup(repo => repo.GetMany(null)).Returns(GetListBlog());
var controller = new BlogController(null,mockRepo.Object);
var result = controller.Index();
var viewResult = Assert.IsType<ViewResult>(result);
var model = Assert.IsAssignableFrom<IEnumerable<Blog>>(viewResult.ViewData.Model);
Assert.Equal(2, model.Count());
}
}
更新(感谢@Gopal Krishnan的评论):
随着Moq >= 4.15.0，以下代码正在工作(不再需要强制转换):
loggerMock.Verify(
x => x.Log(
LogLevel.Information,
It.IsAny<EventId>(),
It.Is<It.IsAnyType>((o, t) => string.Equals("Index page say hello", o.ToString(), StringComparison.InvariantCultureIgnoreCase)),
It.IsAny<Exception>(),
It.IsAny<Func<It.IsAnyType, Exception?, string>>()),
Times.Once);
之前版本的答案(Moq < 4.15.0):
对于使用Moq的。net core 3答案
https://stackoverflow.com/a/54646657/2164198
https://stackoverflow.com/a/54809607/2164198
https://stackoverflow.com/a/56728528/2164198
由于在ILogger.Log中的TState曾经是对象，现在是FormattedLogValues问题中描述的变化，不再工作
幸运的是，stakx提供了一个很好的解决方案。所以我把它贴出来，希望能帮别人节省时间(花了一段时间才弄明白):
loggerMock.Verify(
x => x.Log(
LogLevel.Information,
It.IsAny<EventId>(),
It.Is<It.IsAnyType>((o, t) => string.Equals("Index page say hello", o.ToString(), StringComparison.InvariantCultureIgnoreCase)),
It.IsAny<Exception>(),
(Func<It.IsAnyType, Exception, string>) It.IsAny<object>()),
Times.Once);
仅仅创建一个虚拟的ILogger对于单元测试来说没有多大价值。您还应该验证是否进行了日志记录调用。您可以使用Moq注入一个模拟ILogger，但验证调用可能有点棘手。本文将深入探讨如何使用Moq进行验证。
下面是文章中一个非常简单的例子:
_loggerMock.Verify(l => l.Log(
LogLevel.Information,
It.IsAny<EventId>(),
It.IsAny<It.IsAnyType>(),
It.IsAny<Exception>(),
(Func<It.IsAnyType, Exception, string>)It.IsAny<object>()), Times.Exactly(1));
它验证是否记录了信息消息。但是，如果我们想验证关于消息的更复杂的信息，比如消息模板和命名属性，这就变得更加棘手了:
_loggerMock.Verify
(
l => l.Log
(
//Check the severity level
LogLevel.Error,
//This may or may not be relevant to your scenario
It.IsAny<EventId>(),
//This is the magical Moq code that exposes internal log processing from the extension methods
It.Is<It.IsAnyType>((state, t) =>
//This confirms that the correct log message was sent to the logger. {OriginalFormat} should match the value passed to the logger
//Note: messages should be retrieved from a service that will probably store the strings in a resource file
CheckValue(state, LogTest.ErrorMessage, "{OriginalFormat}") &&
//This confirms that an argument with a key of "recordId" was sent with the correct value
//In Application Insights, this will turn up in Custom Dimensions
CheckValue(state, recordId, nameof(recordId))
),
//Confirm the exception type
It.IsAny<NotImplementedException>(),
//Accept any valid Func here. The Func is specified by the extension methods
(Func<It.IsAnyType, Exception, string>)It.IsAny<object>()),
//Make sure the message was logged the correct number of times
Times.Exactly(1)
);
我相信您可以用其他模拟框架做同样的事情，但是ILogger接口确保了这很困难。
实际上，我找到了Microsoft.Extensions.Logging.Abstractions。NullLogger<>，这看起来像是一个完美的解决方案。安装包Microsoft.Extensions.Logging。抽象，然后按照示例配置和使用它:
using Microsoft.Extensions.Logging;
public void ConfigureServices(IServiceCollection services)
{
...
services.AddSingleton<ILoggerFactory, NullLoggerFactory>();
...
}
using Microsoft.Extensions.Logging;
public class MyClass : IMyClass
{
public const string ErrorMessageILoggerFactoryIsNull = "ILoggerFactory is null";
private readonly ILogger<MyClass> logger;
public MyClass(ILoggerFactory loggerFactory)
{
if (null == loggerFactory)
{
throw new ArgumentNullException(ErrorMessageILoggerFactoryIsNull, (Exception)null);
}
this.logger = loggerFactory.CreateLogger<MyClass>();
}
}
单元测试
//using Microsoft.VisualStudio.TestTools.UnitTesting;
//using Microsoft.Extensions.Logging;
[TestMethod]
public void SampleTest()
{
ILoggerFactory doesntDoMuch = new Microsoft.Extensions.Logging.Abstractions.NullLoggerFactory();
IMyClass testItem = new MyClass(doesntDoMuch);
Assert.IsNotNull(testItem);
}
