Add new Log4JFormatter static property

Author: 0xced

src/Log4NetTextFormatter.cs

@@ -49,6 +49,13 @@ public class Log4NetTextFormatter : ITextFormatter
     private readonly Log4NetTextFormatterOptions _options;
     private readonly bool _usesLog4JCompatibility;
 
+    /// <summary>
+    /// A <see cref="Log4NetTextFormatter"/> instance configured for the log4j XML layout.
+    /// Accessible with <c>Serilog.Formatting.Log4Net.Log4NetTextFormatter::Log4JFormatter, Serilog.Formatting.Log4Net</c> when using the
+    /// <a href="https://github.com/serilog/serilog-settings-configuration/">Serilog.Settings.Configuration</a> package.
+    /// </summary>
+    public static Log4NetTextFormatter Log4JFormatter { get; } = new(c => c.UseLog4JCompatibility());
+
     /// <summary>
     /// Initialize a new instance of the <see cref="Log4NetTextFormatter"/> class.
     /// </summary>

tests/Log4NetTextFormatterTest.cs

@@ -306,22 +306,24 @@ public Task DefaultFormatProvider()
         return Verify(output);
     }
 
-    [Fact]
-    public Task Log4JCompatibility()
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public Task Log4JCompatibility(bool useStaticInstance)
     {
         // Arrange
         using var output = new StringWriter();
         var logEvent = CreateLogEvent(
             exception: new Exception("An error occurred").SetStackTrace(@"  at Serilog.Formatting.Log4Net.Tests.Log4NetTextFormatterTest.BasicMessage_WithException() in Log4NetTextFormatterTest.cs:123"),
             properties: new LogEventProperty("π", new ScalarValue(3.14m))
         );
-        var formatter = new Log4NetTextFormatter(c => c.UseLog4JCompatibility());
+        var formatter = useStaticInstance ? Log4NetTextFormatter.Log4JFormatter : new Log4NetTextFormatter(c => c.UseLog4JCompatibility());
 
         // Act
         formatter.Format(logEvent, output);
 
         // Assert
-        return Verify(output);
+        return Verify(output).DisableRequireUniquePrefix();
     }
 
     [Fact]

tests/PublicApi.net6.0.verified.cs

@@ -31,6 +31,7 @@ public class Log4NetTextFormatter : Serilog.Formatting.ITextFormatter
     {
         public Log4NetTextFormatter() { }
         public Log4NetTextFormatter(System.Action<Serilog.Formatting.Log4Net.Log4NetTextFormatterOptionsBuilder>? configureOptions) { }
+        public static Serilog.Formatting.Log4Net.Log4NetTextFormatter Log4JFormatter { get; }
         public void Format(Serilog.Events.LogEvent logEvent, System.IO.TextWriter output) { }
     }
     public class Log4NetTextFormatterOptionsBuilder

tests/PublicApi.netstandard2.0.verified.cs

@@ -31,6 +31,7 @@ public class Log4NetTextFormatter : Serilog.Formatting.ITextFormatter
     {
         public Log4NetTextFormatter() { }
         public Log4NetTextFormatter(System.Action<Serilog.Formatting.Log4Net.Log4NetTextFormatterOptionsBuilder>? configureOptions) { }
+        public static Serilog.Formatting.Log4Net.Log4NetTextFormatter Log4JFormatter { get; }
         public void Format(Serilog.Events.LogEvent logEvent, System.IO.TextWriter output) { }
     }
     public class Log4NetTextFormatterOptionsBuilder