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());
    }
}

当前回答

如果还是实际的。简单的方法在。net core >= 3的测试中输出日志

[Fact]
public void SomeTest()
{
    using var logFactory = LoggerFactory.Create(builder => builder.AddConsole());
    var logger = logFactory.CreateLogger<AccountController>();
    
    var controller = new SomeController(logger);

    var result = controller.SomeActionAsync(new Dto{ ... }).GetAwaiter().GetResult();
}

其他回答

前面已经提到过,您可以将其模拟为任何其他接口。

var logger = new Mock<ILogger<QueuedHostedService>>();

到目前为止一切顺利。

好的一点是,您可以使用Moq来验证某些调用是否已经执行。例如,在这里,我检查日志已经被一个特定的异常调用。

logger.Verify(m => m.Log(It.Is<LogLevel>(l => l == LogLevel.Information), 0,
            It.IsAny<object>(), It.IsAny<TaskCanceledException>(), It.IsAny<Func<object, Exception, string>>()));

在使用Verify时,重点是针对ILooger接口中的真实Log方法,而不是扩展方法进行验证。

如果还是实际的。简单的方法在。net core >= 3的测试中输出日志

[Fact]
public void SomeTest()
{
    using var logFactory = LoggerFactory.Create(builder => builder.AddConsole());
    var logger = logFactory.CreateLogger<AccountController>();
    
    var controller = new SomeController(logger);

    var result = controller.SomeActionAsync(new Dto{ ... }).GetAwaiter().GetResult();
}

当使用StructureMap / Lamar时:

var c = new Container(_ =>
{
    _.For(typeof(ILogger<>)).Use(typeof(NullLogger<>));
});

文档:

https://learn.microsoft.com/en-us/dotnet/api/microsoft.extensions.logging.abstractions.nulllogger?view=aspnetcore-2.1 http://structuremap.github.io/generics/

@Mahmoud 哈纳菲

我更新了你的答案,以配合当前的状态。

static class MockLogHelper
{
    public static ISetup<ILogger<T>> MockLog<T>(this Mock<ILogger<T>> logger, LogLevel level)
    {
        return logger.Setup(x => x.Log(level, It.IsAny<EventId>(), It.IsAny<It.IsAnyType>(), It.IsAny<Exception>(), (Func<It.IsAnyType, Exception, string>)It.IsAny<object>()));
        //return logger.Setup(x => x.Log(level, It.IsAny<EventId>(), It.IsAny<object>(), It.IsAny<Exception>(), It.IsAny<Func<object, Exception, string>>()));
    }

    private static Expression<Action<ILogger<T>>> Verify<T>(LogLevel level)
    {
        return x => x.Log(level, 0, It.IsAny<It.IsAnyType>(), It.IsAny<Exception>(), (Func<It.IsAnyType, Exception, string>)It.IsAny<object>());
        //return x => x.Log(level, 0, It.IsAny<object>(), It.IsAny<Exception>(), It.IsAny<Func<object, Exception, string>>());
    }

    public static void Verify<T>(this Mock<ILogger<T>> mock, LogLevel level, Times times)
    {
        mock.Verify(Verify<T>(level), times);
    }
}

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);