Add support for Enrich.With()

Support for `Enrich.With(ILogEventEnricher enricher)`

Author: tsimbalar

src/Serilog.Settings.Configuration/Settings/Configuration/SurrogateConfigurationMethods.cs

@@ -60,6 +60,7 @@ public static IEnumerable<MethodInfo> Enrich
             get
             {
                 yield return GetSurrogateConfigurationMethod<LoggerEnrichmentConfiguration, object, object>((c, _, __) => FromLogContext(c));
+                yield return GetSurrogateConfigurationMethod<LoggerEnrichmentConfiguration, ILogEventEnricher, object>((c, e, __) => With(c, e));
             }
         }
 
@@ -132,5 +133,10 @@ static LoggerConfiguration AsScalar(LoggerDestructuringConfiguration loggerDestr
         static LoggerConfiguration FromLogContext(LoggerEnrichmentConfiguration loggerEnrichmentConfiguration)
             => loggerEnrichmentConfiguration.FromLogContext();
 
+        static LoggerConfiguration With(LoggerEnrichmentConfiguration loggerEnrichmentConfiguration, ILogEventEnricher enricher)
+        {
+            return loggerEnrichmentConfiguration.With(enricher);
+        }
+
     }
 }

test/Serilog.Settings.Configuration.Tests/ConfigurationSettingsTests.cs

@@ -962,5 +962,34 @@ public void AuditToSinkIsAppliedWithCustomSinkAndLevelSwitch()
 
             Assert.Single(DummyRollingFileSink.Emitted);
         }
+
+        
+        [Fact]
+        public void EnrichWithIsAppliedWithCustomEnricher()
+        {
+            LogEvent evt = null;
+
+            var json = $@"{{
+                ""Serilog"": {{
+                    ""Using"": [""TestDummies""],
+                    ""Enrich"": [
+                    {{
+                        ""Name"": ""With"",
+                        ""Args"": {{
+                            ""enricher"": ""{typeof(DummyThreadIdEnricher).AssemblyQualifiedName}""
+                        }}
+                    }}]
+                }}
+            }}";
+
+            var log = ConfigFromJson(json)
+                .WriteTo.Sink(new DelegatingSink(e => evt = e))
+                .CreateLogger();
+
+            log.Write(Some.InformationEvent());
+
+            Assert.NotNull(evt);
+            Assert.True(evt.Properties.ContainsKey("ThreadId"), "Event should have enriched property ThreadId");
+        }
     }
 }

test/TestDummies/DummyThreadIdEnricher.cs

@@ -6,7 +6,9 @@ namespace TestDummies
     public class DummyThreadIdEnricher : ILogEventEnricher
     {
         public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
-        {          
+        {
+            logEvent.AddPropertyIfAbsent(propertyFactory
+                .CreateProperty("ThreadId", "SomeId"));
         }
     }
 }