c# – .net core 2.0 ConfigureLogging xunit test

If you used xUnit.net 1.x,you may have previously been writing output to Console,Debug,or Trace. When xUnit.net v2 shipped with parallelization turned on by default,this output capture mechanism was no longer appropriate; it is impossible to know which of the many tests that could be running in parallel were responsible for writing to those shared resources.

相反,您现在应该使用an explicit mechanism来写入测试输出.基本上,您不是写入控制台,而是写入特殊的ITestOutputHelper.

当然,ASP.NET Core日志记录默认不支持此输出机制.幸运的是,为测试输出编写日志记录提供程序并不困难.我刚刚实现了一个快速提供程序,并在下面的答案中包含它.你可以像这样使用它：

public class Example
{
    private readonly ILogger<Example> _logger;

    public Example(ITestOutputHelper testOutputHelper)
    {
        var loggerFactory = new LoggerFactory();
        loggerFactory.AddProvider(new XunitLoggerProvider(testOutputHelper));
        _logger = loggerFactory.CreateLogger<Example>();
    }

    [Fact]
    public void Test()
    {
        _logger.LogDebug("Foo bar baz");
    }
}

请注意,通常应避免在单元测试中创建完整的依赖项注入容器.在单元测试中使用DI通常表明您的单元测试不是单元测试,而是集成测试.在单元测试中,您应该只测试一个特定单元并明确地传递其所有依赖项 – 而不仅仅是作为模拟.正如您在上面的示例中所看到的,创建记录器实际上是一个非常简单的事情,没有DI.

正如所承诺的,这是运行上面显示的代码所需的XunitLoggerProvider和XunitLogger,以及将Microsoft.Extensions.Logging框架与xUnit测试输出集成：

public class XunitLoggerProvider : ILoggerProvider
{
    private readonly ITestOutputHelper _testOutputHelper;

    public XunitLoggerProvider(ITestOutputHelper testOutputHelper)
    {
        _testOutputHelper = testOutputHelper;
    }

    public ILogger CreateLogger(string categoryName)
        => new XunitLogger(_testOutputHelper,categoryName);

    public void Dispose()
    { }
}

public class XunitLogger : ILogger
{
    private readonly ITestOutputHelper _testOutputHelper;
    private readonly string _categoryName;

    public XunitLogger(ITestOutputHelper testOutputHelper,string categoryName)
    {
        _testOutputHelper = testOutputHelper;
        _categoryName = categoryName;
    }

    public IDisposable BeginScope<TState>(TState state)
        => NoopDisposable.Instance;

    public bool IsEnabled(LogLevel logLevel)
        => true;

    public void Log<TState>(LogLevel logLevel,EventId eventId,TState state,Exception exception,Func<TState,Exception,string> formatter)
    {
        _testOutputHelper.WriteLine($"{_categoryName} [{eventId}] {formatter(state,exception)}");
        if (exception != null)
            _testOutputHelper.WriteLine(exception.ToString());
    }

    private class NoopDisposable : IDisposable
    {
        public static NoopDisposable Instance = new NoopDisposable();
        public void Dispose()
        { }
    }
}