Default to nesting (un-flattening) dotted property names

sample/Sample/Program.cs

@@ -3,6 +3,9 @@
 using System.Threading;
 using Serilog;
 using Serilog.Core;
+using Serilog.Debugging;
+
+SelfLog.Enable(Console.Error);
 
 // By sharing between the Seq sink and logger itself,
 // Seq API keys can be used to control the level of the whole logging pipeline.

src/Serilog.Sinks.Seq/Serilog.Sinks.Seq.csproj

@@ -29,9 +29,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Serilog" Version="4.0.0" />
+    <PackageReference Include="Serilog" Version="4.1.0" />
     <PackageReference Include="Nullable" Version="1.3.1" PrivateAssets="All" />
-    <PackageReference Include="Serilog.Sinks.File" Version="5.0.0" />
+    <PackageReference Include="Serilog.Sinks.File" Version="6.0.0" />
   </ItemGroup>
 
   <ItemGroup>

src/Serilog.Sinks.Seq/Sinks/Seq/Conventions/PreserveDottedPropertyNames.cs

@@ -21,7 +21,7 @@ namespace Serilog.Sinks.Seq.Conventions;
 /// Maintains verbatim processing of property names. A property named <c>"a.b"</c> will be transmitted to Seq as a
 /// scalar value with name <c>"a.b"</c>.
 /// </summary>
-class PreserveDottedPropertyNames: IDottedPropertyNameConvention
+sealed class PreserveDottedPropertyNames: IDottedPropertyNameConvention
 {
     /// <inheritdoc />
     public IReadOnlyDictionary<string, LogEventPropertyValue> ProcessDottedPropertyNames(IReadOnlyDictionary<string, LogEventPropertyValue> maybeDotted)

src/Serilog.Sinks.Seq/Sinks/Seq/Conventions/UnflattenDottedPropertyNames.cs

@@ -21,12 +21,12 @@
 namespace Serilog.Sinks.Seq.Conventions;
 
 /// <summary>
-/// Experimental. Unflatten property names. A property with name <c>"a.b"</c> will be transmitted to Seq as
+/// Nest (un-flatten) properties with dotted names. A property with name <c>"a.b"</c> will be transmitted to Seq as
 /// a structure with name <c>"a"</c>, and one member <c>"b"</c>.
 /// </summary>
 /// <remarks>This behavior is enabled when the <c>Serilog.Parsing.MessageTemplateParser.AcceptDottedPropertyNames</c>
 /// <see cref="AppContext"/> switch is set to value <c langword="true"/>.</remarks>
-class UnflattenDottedPropertyNames: IDottedPropertyNameConvention
+sealed class UnflattenDottedPropertyNames: IDottedPropertyNameConvention
 {
     const int MaxDepth = 10;
 

src/Serilog.Sinks.Seq/Sinks/Seq/SeqCompactJsonFormatter.cs

@@ -32,27 +32,27 @@ namespace Serilog.Sinks.Seq;
 /// </summary>
 /// <remarks>Modified from <c>Serilog.Formatting.Compact.CompactJsonFormatter</c> to add
 /// implicit SerilogTracing span support.</remarks>
-public class SeqCompactJsonFormatter: ITextFormatter
+public sealed class SeqCompactJsonFormatter: ITextFormatter
 {
-    readonly IDottedPropertyNameConvention _dottedPropertyNameConvention;
     readonly JsonValueFormatter _valueFormatter;
     readonly IFormatProvider _formatProvider;
-
+    readonly IDottedPropertyNameConvention _dottedPropertyNameConvention;
+
     /// <summary>
     /// Construct a <see cref="SeqCompactJsonFormatter"/>.
     /// </summary>
     /// <param name="valueFormatter">A value formatter for <see cref="LogEventPropertyValue"/>s on the event.</param>
     /// <param name="formatProvider">An <see cref="IFormatProvider"/> that will be used to render log event tokens.</param>
-    public SeqCompactJsonFormatter(IFormatProvider? formatProvider = null, JsonValueFormatter? valueFormatter = null)
+    /// <param name="preserveDottedPropertyNames">If <c langword="true"/>, log event property names that
+    /// contain <c>.</c> will be sent to Seq as-is. Otherwise, properties with dotted names will be converted
+    /// into nested objects.</param>
+    public SeqCompactJsonFormatter(IFormatProvider? formatProvider = null, JsonValueFormatter? valueFormatter = null, bool preserveDottedPropertyNames = false)
     {
-        var acceptDottedPropertyNames = AppContext.TryGetSwitch("Serilog.Parsing.MessageTemplateParser.AcceptDottedPropertyNames", out var accept) && accept;
-
-        _dottedPropertyNameConvention = acceptDottedPropertyNames ?
-            new UnflattenDottedPropertyNames() :
-            new PreserveDottedPropertyNames();
-
         _formatProvider = formatProvider ?? CultureInfo.InvariantCulture;
         _valueFormatter = valueFormatter ?? new("$type");
+        _dottedPropertyNameConvention = preserveDottedPropertyNames
+            ? new PreserveDottedPropertyNames()
+            : new UnflattenDottedPropertyNames();
     }
 
     /// <summary>
@@ -182,4 +182,4 @@ public void FormatEvent(LogEvent logEvent, TextWriter output)
 
         output.Write('}');
     }
-}
+}

test/Serilog.Sinks.Seq.Tests/SeqCompactJsonFormatterTests.cs

@@ -79,6 +79,14 @@ public void MultiplePropertiesAreDelimited()
         AssertValidJson(log => log.Information("Property {First} and {Second}", "One", "Two"));
     }
 
+    [Fact]
+    public void DottedPropertiesAreNested()
+    {
+        dynamic evt = AssertValidJson(log => log.Information("Property {a.b} and {a.c}", "One", "Two"));
+        Assert.Equal("One", (string)evt.a.b);
+        Assert.Equal("Two", (string)evt.a.c);
+    }
+
     [Fact]
     public void ExceptionsAreFormattedToValidJson()
     {