Serilog (C#): How to get current MethodName, FileName/Path and LineNumber without reflection

Description.md

Serilog (C#): How to get the current MethodName, FileName/Path and LineNumber without reflection

This is a simple setup for reflectionless logging with serilog using caller information (and a single static class).

See also https://stackoverflow.com/a/46905798

Log.cs

Create your own Log.cs in your Root-Namespace (you can use the class below).

This class is required to detect where the call is coming from; it uses Caller-Information to speed up the program execution, because the attributes are resolved at compile-time.

You can now also remove all using Serilog;-imports - if you have any - in the classes where you want to log, because the Log.cs is everywhere in the namespace visble and easy accessible.

Serilog-Output Template

Now you can use the added properties (here: MemberName, FilePath, FileName, LineNumber) in your outputTemplate:

⚠️ Note: For more performance you can remove/uncomment unused properties, here e.g. FilePath and LineNumber in SetContext(...)

Final Example

OutputTemplate: {Timestamp:HH:mm:ss,fff} {Level:u3} {FileName} [{MemberName}] {Message:lj}{NewLine}{Exception}

namespace Demo
{
  public class TestClass
  {
    public void TestMethod()
    {
      Log.Info("Some test");
    }
  }
}

Produces the following output: 18:16:40,183 INFO TestClass [TestMethod] Some test

Changelog

• 2020-03-21: Tuned docs a bit; updated and reformatted the Log.cs class
• 2020-05-29: Tuned docs a bit; Reformatted the Log.cs; References to CoreFramework.Logging

Log.cs

// MIT License
// Copyright (c) 2020 litetex
// See also https://github.com/litetex/CoreFramework/blob/develop/CoreFramework.Logging/Log.cs

using System;
using System.IO;
using System.Runtime.CompilerServices;

namespace CoreFramework
{
   public static class Log
   {
      private static string FormatForException(this string message, Exception ex)
      {
         return $"{message}: {(ex != null ? ex.ToString() : "")}";
      }

      private static string FormatForContext(
         this string message, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {
         var fileName = Path.GetFileNameWithoutExtension(sourceFilePath);
         var methodName = memberName;

         return $"{fileName} [{methodName}] {message}";
      }

      public static void Verbose(
         string message, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {
         Serilog.Log.Verbose(
            message
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Verbose(
         string message, 
         Exception ex, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {
         Serilog.Log.Verbose(
            message
               .FormatForException(ex)
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Verbose(
         Exception ex,
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {

         Serilog.Log.Verbose(
            (ex != null ? ex.ToString() : "")
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Debug(
         string message, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {
         Serilog.Log.Debug(
            message
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Debug(
         string message, 
         Exception ex, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {
         Serilog.Log.Debug(
            message
               .FormatForException(ex)
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Debug(
         Exception ex,
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {

         Serilog.Log.Debug(
            (ex != null ? ex.ToString() : "")
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Info(
         string message, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {
         Serilog.Log.Information(
            message
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Info(
         string message, 
         Exception ex, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {

         Serilog.Log.Information(
            message
               .FormatForException(ex)
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Info(
         Exception ex,
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {

         Serilog.Log.Information(
            (ex != null ? ex.ToString() : "")
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Warn(string message, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {

         Serilog.Log.Warning(
            message
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Warn(
         string message, 
         Exception ex, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {

         Serilog.Log.Warning(
            message
               .FormatForException(ex)
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Warn(
         Exception ex,
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {

         Serilog.Log.Warning(
            (ex != null ? ex.ToString() : "")
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Error(
         string message, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {

         Serilog.Log.Error(
            message
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
           );
      }

      public static void Error(
         string message, 
         Exception ex,
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {

         Serilog.Log.Error(
            message
               .FormatForException(ex)
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Error(
         Exception ex, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {

         Serilog.Log.Error(
            (ex != null ? ex.ToString() : "")
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Fatal(
         string message, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {
         FatalAction();

         Serilog.Log.Error(
            message
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Fatal(
         string message, 
         Exception ex, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {
         FatalAction();

         Serilog.Log.Error(
            message
               .FormatForException(ex)
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      public static void Fatal(
         Exception ex, 
         [CallerMemberName] string memberName = "",
         [CallerFilePath] string sourceFilePath = "",
         [CallerLineNumber] int sourceLineNumber = 0)
      {
         FatalAction();

         Serilog.Log.Error(
            (ex != null ? ex.ToString() : "")
               .FormatForContext(memberName, sourceFilePath, sourceLineNumber)
            );
      }

      private static void FatalAction()
      {
         Environment.ExitCode = -1;
      }
   }
}

Nice job @morteng85 ! That works with the message templates! I just needed to implement the Constants, added .Enrich.With<InvocationContextEnricher>() to the LoggerConfiguration instatiation, and the appropriate outputTemplate in my Sink(s), and it all worked! 🙇