xUnit ILogger

This library is a relatively simple wrapper for the ITestOutputHelper provided by xUnit. When doing integration tests, often the system logs to ILogger instances created via Dependency Injection. This it problematic for capturing the logs from the tests - which are usually handy for debugging what went wrong in the test!

This ILoggingProvider (and associated ILogger) implementation allows you to wrap the ITestOutputHelper that xUnit provides and pass it to your system by registering it as a Logging Provider. This will result in your system's normal logging being captured and available in the test output logs.

Typically you would register the ILoggingProvider in a ConfigureServices method by accessing the ILoggingBuilder provider therein.

Example:

public class TestBase {
        protected readonly ITestOutputHelper output;
        protected readonly TestServer server;
        protected TestBase(ITestOutputHelper output)
        {
            this.output = output;
            server = new TestServer(
                new WebHostBuilder()
                    .ConfigureLogging(lb =>
                        lb.AddConsole()
                          .AddProvider(new XUnitLoggerProvider(output))
                    )
                    .UseStartup<Startup>()
            );
        }
}

You will likely have more complex WebHostBuilder setup than this example. The example is only meant to illustrate the registration of the ILoggingProvder.

The XUnitLoggingProvider also supports reading some configuration from an IConfiguration instance so if you have loaded up confgiuration, you can pass it in the constructor.

Example:

appsettings.Tests.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Debug",
      "Microsoft": "Trace",
      "Microsoft.Hosting.Lifetime": "Debug"
    }
  },
  "Xunit": {
    "LogLevel": "Debug",
    "LogFormat": "Unformatted"
  }
}

Test class:

public class TestBase {
        protected readonly ITestOutputHelper output;
        protected readonly TestServer server;
        protected TestBase(ITestOutputHelper output)
        {
            string baseAppSettingsFilename = "appsettings.json";
            IConfigurationBuilder ConfigurationBuilder = new ConfigurationBuilder()
                .AddJsonFile(
                     path: baseAppSettingsFilename,
                     optional: false,
                     reloadOnChange: false)
                .AddJsonFile(
                     path: baseAppSettingsFilename.Replace(".json", $".{Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT")}.json"),
                     optional: false,
                     reloadOnChange: false)
                .AddJsonFile(
                     path: baseAppSettingsFilename.Replace(".json", $".Tests.json"),
                     optional: false,
                     reloadOnChange: false)
                .AddEnvironmentVariables()
                ;
            IConfiguration config = ConfigurationBuilder.Build();
            this.output = output;
            server = new TestServer(
                new WebHostBuilder()
                    .ConfigureLogging(lb =>
                        lb.AddConsole()
                          .AddProvider(new XUnitLoggerProvider(output))
                    )
                    .UseStartup<Startup>()
            );
        }
}

Configuration

LogLevel is read from settings in this priority:

1. Logging:LogLevel:Xunit:LogLevel
2. Logging:Xunit:LogLevel
3. Logging:LogLevel:Xunit
4. Logging:LogLevel:Default

LogFormat is read from settings in this priority:

1. Logging:Xunit:LogFormat
2. Logging:LogLevel:Xunit:LogFormat

If you're using ILogger extensions to re-format the log messages, set the LogFormat to Unformatted.

The default log output tries to emulate close to the Microsoft log format:

{LogLevel}: [{CategoryName}] 
            {formatter output}
{exception}
            => {scope} 

Change Log

• 0.1.0 : Initial Release