Add support for Serilog.Enrichers.WithCaller / locationInfo

Also update README and CHANGELOG for version 1.1.0

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.1.0][1.1.0] - 2023-05-02
+
+- Add support for caller information (class, method, file, line) through the [Serilog.Enrichers.WithCaller](https://www.nuget.org/packages/Serilog.Enrichers.WithCaller/) package.
+
 ## [1.0.2][1.0.2] - 2023-02-11
 
 - Add a new `Log4NetTextFormatter.Log4JFormatter` static property which is configured for the log4j XML layout. This static property is also useful when using the [Serilog.Settings.Configuration](https://github.com/serilog/serilog-settings-configuration/) package where it can be used with the following accessor:
@@ -80,6 +84,7 @@ Still trying to figure out how to make everything fit together with [MinVer](htt
 
 - Implement log4j compatibility mode.
 
+[1.1.0]: https://github.com/serilog-contrib/serilog-formatting-log4net/compare/1.0.2...1.1.0
 [1.0.2]: https://github.com/serilog-contrib/serilog-formatting-log4net/compare/1.0.1...1.0.2
 [1.0.1]: https://github.com/serilog-contrib/serilog-formatting-log4net/compare/1.0.0...1.0.1
 [1.0.0]: https://github.com/serilog-contrib/serilog-formatting-log4net/compare/1.0.0-rc.4...1.0.0

README.md

@@ -192,14 +192,25 @@ Include the machine name in log4net events by using [Serilog.Enrichers.Environme
 var loggerConfiguration = new LoggerConfiguration().Enrich.WithMachineName();
 ```
 
-Combining these three enrichers will produce a log event including `thread`, `domain` and `username` attributes plus a `log4net:HostName` property containing the machine name:
+### Caller
+
+Include caller information (class, method, file, line) by using [Serilog.Enrichers.WithCaller](https://www.nuget.org/packages/Serilog.Enrichers.WithCaller/):
+
+```c#
+var loggerConfiguration = new LoggerConfiguration().Enrich.WithCaller(includeFileInfo: true);
+```
+
+### All together
+
+Combining these four enrichers will produce a log event including `thread`, `domain` and `username` attributes, a `log4net:HostName` property containing the machine name and a `locationInfo` element:
 
 ```xml
 <event timestamp="2020-06-28T10:07:33.314159+02:00" level="INFO" thread="1" domain="TheDomainName" username="TheUserName">
   <properties>
     <data name="log4net:HostName" value="TheMachineName" />
   </properties>
   <message>The message</message>
+  <locationInfo class="Program" method="Main(System.String[])" file="/Absolute/Path/To/Program.cs" line="29" />
 </event>
 ```
 

src/Log4NetTextFormatter.cs

@@ -3,6 +3,7 @@
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
+using System.Text.RegularExpressions;
 using System.Xml;
 using Serilog.Core;
 using Serilog.Events;
@@ -25,7 +26,7 @@ public class Log4NetTextFormatter : ITextFormatter
     /// </summary>
     private static readonly string[] SpecialProperties = {
         Constants.SourceContextPropertyName, OutputProperties.MessagePropertyName,
-        ThreadIdPropertyName, UserNamePropertyName, MachineNamePropertyName
+        ThreadIdPropertyName, UserNamePropertyName, MachineNamePropertyName, CallerPropertyName
     };
 
     /// <summary>
@@ -46,6 +47,17 @@ public class Log4NetTextFormatter : ITextFormatter
     /// <remarks>https://github.com/serilog/serilog-enrichers-environment/blob/v2.1.3/src/Serilog.Enrichers.Environment/Enrichers/MachineNameEnricher.cs#L36</remarks>
     private const string MachineNamePropertyName = "MachineName";
 
+    /// <summary>
+    /// The name of the caller property, set by <a href="https://www.nuget.org/packages/Serilog.Enrichers.WithCaller/">Serilog.Enrichers.WithCaller</a>
+    /// </summary>
+    /// <remarks>https://github.com/pmetz-steelcase/Serilog.Enrichers.WithCaller/blob/1.2.0/Serilog.Enrichers.WithCaller/CallerEnricher.cs#L66</remarks>
+    private const string CallerPropertyName = "Caller";
+
+    /// <summary>
+    /// The regular exception matching "class", "method", and optionally "file" and "line" for the caller property.
+    /// </summary>
+    private static readonly Regex CallerRegex = new(@"(?<class>.*)\.(?<method>.*\(.*\))(?: (?<file>.*):(?<line>\d+))?", RegexOptions.Compiled);
+
     private readonly Log4NetTextFormatterOptions _options;
     private readonly bool _usesLog4JCompatibility;
 
@@ -139,6 +151,7 @@ private void WriteEvent(LogEvent logEvent, XmlWriter writer)
         }
         WriteMessage(logEvent, writer);
         WriteException(logEvent, writer);
+        WriteLocationInfo(logEvent, writer);
         writer.WriteEndElement();
     }
 
@@ -423,6 +436,31 @@ private void WriteException(LogEvent logEvent, XmlWriter writer)
         }
     }
 
+    /// <summary>
+    /// Write location information associated to the log event, i.e. class, method, file and line where the event originated.
+    /// If the event was not enriched with caller information then nothing is written.
+    /// </summary>
+    /// <param name="logEvent">The log event.</param>
+    /// <param name="writer">The XML writer.</param>
+    /// <remarks>https://github.com/apache/logging-log4net/blob/rel/2.0.8/src/Layout/XmlLayout.cs#L297-L307</remarks>
+    /// <remarks>https://github.com/apache/log4j/blob/v1_2_17/src/main/java/org/apache/log4j/xml/XMLLayout.java#L170-L181</remarks>
+    private void WriteLocationInfo(LogEvent logEvent, XmlWriter writer)
+    {
+        if (logEvent.Properties.TryGetValue(CallerPropertyName, out var callerProperty) && callerProperty is ScalarValue { Value: string caller })
+        {
+            var match = CallerRegex.Match(caller);
+            if (match.Success)
+            {
+                WriteStartElement(writer, "locationInfo");
+                writer.WriteAttributeString("class", match.Groups[1].Value);
+                writer.WriteAttributeString("method", match.Groups[2].Value);
+                writer.WriteAttributeString("file", match.Groups[3].Value);
+                writer.WriteAttributeString("line", match.Groups[4].Value);
+                writer.WriteEndElement();
+            }
+        }
+    }
+
     /// <summary>
     /// Start writing an XML element, taking into account the configured <see cref="Log4NetTextFormatterOptions.XmlNamespace"/>.
     /// </summary>

tests/Log4NetTextFormatterTest.Caller.verified.xml

@@ -0,0 +1,4 @@
+<log4net:event timestamp="2003-01-04T15:09:26.535+01:00" level="INFO" xmlns:log4net="http://logging.apache.org/log4net/schemas/log4net-events-1.2/">
+  <log4net:message><![CDATA[Hello from Serilog]]></log4net:message>
+  <log4net:locationInfo class="Fully.Qualified.ClassName" method="MethodName(System.String)" file="" line="" />
+</log4net:event>

tests/Log4NetTextFormatterTest.CallerLog4J.verified.xml

@@ -0,0 +1,4 @@
+<log4j:event timestamp="1041689366535" level="INFO">
+  <log4j:message><![CDATA[Hello from Serilog]]></log4j:message>
+  <log4j:locationInfo class="Fully.Qualified.ClassName" method="MethodName(System.String)" file="" line="" />
+</log4j:event>

tests/Log4NetTextFormatterTest.CallerNonScalar.verified.xml

@@ -0,0 +1,3 @@
+<log4net:event timestamp="2003-01-04T15:09:26.535+01:00" level="INFO" xmlns:log4net="http://logging.apache.org/log4net/schemas/log4net-events-1.2/">
+  <log4net:message><![CDATA[Hello from Serilog]]></log4net:message>
+</log4net:event>

tests/Log4NetTextFormatterTest.CallerWithFile.verified.xml

@@ -0,0 +1,4 @@
+<log4net:event timestamp="2003-01-04T15:09:26.535+01:00" level="INFO" xmlns:log4net="http://logging.apache.org/log4net/schemas/log4net-events-1.2/">
+  <log4net:message><![CDATA[Hello from Serilog]]></log4net:message>
+  <log4net:locationInfo class="Fully.Qualified.ClassName" method="MethodName(System.String)" file="/Absolute/Path/To/FileName.cs" line="123" />
+</log4net:event>

tests/Log4NetTextFormatterTest.cs

@@ -583,6 +583,70 @@ public Task MachineNamePropertyStructureValue()
         return Verify(output);
     }
 
+    [Fact]
+    public Task Caller()
+    {
+        // Arrange
+        using var output = new StringWriter();
+        var logEvent = CreateLogEvent(properties: new LogEventProperty("Caller", new ScalarValue("Fully.Qualified.ClassName.MethodName(System.String)")));
+
+        var formatter = new Log4NetTextFormatter();
+
+        // Act
+        formatter.Format(logEvent, output);
+
+        // Assert
+        return Verify(output);
+    }
+
+    [Fact]
+    public Task CallerNonScalar()
+    {
+        // Arrange
+        using var output = new StringWriter();
+        var logEvent = CreateLogEvent(properties: new LogEventProperty("Caller", new CustomLogEventPropertyValue("")));
+
+        var formatter = new Log4NetTextFormatter();
+
+        // Act
+        formatter.Format(logEvent, output);
+
+        // Assert
+        return Verify(output);
+    }
+
+    [Fact]
+    public Task CallerWithFile()
+    {
+        // Arrange
+        using var output = new StringWriter();
+        var logEvent = CreateLogEvent(properties: new LogEventProperty("Caller", new ScalarValue("Fully.Qualified.ClassName.MethodName(System.String) /Absolute/Path/To/FileName.cs:123")));
+
+        var formatter = new Log4NetTextFormatter();
+
+        // Act
+        formatter.Format(logEvent, output);
+
+        // Assert
+        return Verify(output);
+    }
+
+    [Fact]
+    public Task CallerLog4J()
+    {
+        // Arrange
+        using var output = new StringWriter();
+        var logEvent = CreateLogEvent(properties: new LogEventProperty("Caller", new ScalarValue("Fully.Qualified.ClassName.MethodName(System.String)")));
+
+        var formatter = new Log4NetTextFormatter(c => c.UseLog4JCompatibility());
+
+        // Act
+        formatter.Format(logEvent, output);
+
+        // Assert
+        return Verify(output);
+    }
+
     [Fact]
     public Task SequenceProperty()
     {