Add support for Serilog 3.1 trace @tr and span @sp ids

Author: nblumhardt

src/Serilog.Expressions/Expressions/BuiltInProperty.cs

@@ -25,4 +25,6 @@ static class BuiltInProperty
     public const string Properties = "p";
     public const string Renderings = "r";
     public const string EventId = "i";
+    public const string TraceId = "tr";
+    public const string SpanId = "sp";
 }

src/Serilog.Expressions/Expressions/Compilation/Linq/LinqExpressionCompiler.cs

@@ -206,6 +206,10 @@ protected override ExpressionBody Transform(AmbientNameExpression px)
                 BuiltInProperty.Message => Splice(context => new ScalarValue(Intrinsics.RenderMessage(formatter, context))),
                 BuiltInProperty.Exception => Splice(context =>
                     context.LogEvent.Exception == null ? null : new ScalarValue(context.LogEvent.Exception)),
+                BuiltInProperty.TraceId => Splice(context =>
+                    context.LogEvent.TraceId == null ? null : new ScalarValue(context.LogEvent.TraceId.Value)),
+                BuiltInProperty.SpanId => Splice(context =>
+                    context.LogEvent.SpanId == null ? null : new ScalarValue(context.LogEvent.SpanId.Value)),
                 BuiltInProperty.Timestamp => Splice(context => new ScalarValue(context.LogEvent.Timestamp)),
                 BuiltInProperty.MessageTemplate => Splice(context => new ScalarValue(context.LogEvent.MessageTemplate.Text)),
                 BuiltInProperty.Properties => Splice(context =>

src/Serilog.Expressions/Expressions/Runtime/Coerce.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using Serilog.Events;
 
@@ -77,6 +78,18 @@ public static bool String(LogEventPropertyValue? value, [MaybeNullWhen(false)] o
                 str = sv.Value.ToString()!;
                 return true;
             }
+
+            if (sv.Value is ActivityTraceId traceId)
+            {
+                str = traceId.ToHexString();
+                return true;
+            }
+
+            if (sv.Value is ActivitySpanId spanId)
+            {
+                str = spanId.ToHexString();
+                return true;
+            }
         }
 
         str = default;

src/Serilog.Expressions/Serilog.Expressions.csproj

@@ -14,15 +14,17 @@
     <PackageLicenseExpression>Apache-2.0</PackageLicenseExpression>
     <RepositoryUrl>https://github.com/serilog/serilog-expressions</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Serilog" Version="3.0.1" />
+    <PackageReference Include="Serilog" Version="3.1.0-*" />
     <PackageReference Include="Nullable" Version="1.3.1" PrivateAssets="All" />
   </ItemGroup>
 
   <ItemGroup>
     <None Include="..\..\assets\icon.png" Pack="true" Visible="false" PackagePath="" />
+    <None Include="..\..\README.md" Pack="true" Visible="false" PackagePath="" />
   </ItemGroup>
 
 </Project>

test/Serilog.Expressions.Tests/Cases/expression-evaluation-cases.asv

@@ -304,3 +304,12 @@ undefined() = undefined() ci         ⇶ undefined()
 'test' like '%'                      ⇶ true
 'test' like ''                       ⇶ false
 '' like ''                           ⇶ true
+
+// Built-ins
+
+@m                                   ⇶ 'Hello, World!'
+@mt                                  ⇶ 'Hello, {Name}!'
+tostring(@x) like 'System.DivideByZeroException%' ⇶ true
+@l                                   ⇶ 'Warning'
+@sp                                  ⇶ 'bb1111820570b80e'
+@tr                                  ⇶ '1befc31e94b01d1a473f63a7905f6c9b'

test/Serilog.Expressions.Tests/ExpressionEvaluationTests.cs

@@ -1,7 +1,9 @@
+using System.Diagnostics;
 using System.Globalization;
 using Serilog.Events;
 using Serilog.Expressions.Runtime;
 using Serilog.Expressions.Tests.Support;
+using Serilog.Parsing;
 using Xunit;
 
 namespace Serilog.Expressions.Tests;
@@ -15,14 +17,22 @@ public class ExpressionEvaluationTests
     [MemberData(nameof(ExpressionEvaluationCases))]
     public void ExpressionsAreCorrectlyEvaluated(string expr, string result)
     {
-        var evt = Some.InformationEvent();
-
-        evt.AddPropertyIfAbsent(
-            new("User", new StructureValue(new[]
+        var evt = new LogEvent(
+            new DateTimeOffset(2025, 5, 15, 13, 12, 11, 789, TimeSpan.FromHours(10)),
+            LogEventLevel.Warning,
+            new DivideByZeroException(),
+            new MessageTemplateParser().Parse("Hello, {Name}!"),
+            new []
             {
-                new LogEventProperty("Id", new ScalarValue(42)),
-                new LogEventProperty("Name", new ScalarValue("nblumhardt")),
-            })));
+                new LogEventProperty("Name", new ScalarValue("World")),
+                new LogEventProperty("User", new StructureValue(new[]
+                {
+                    new LogEventProperty("Id", new ScalarValue(42)),
+                    new LogEventProperty("Name", new ScalarValue("nblumhardt")),
+                }))
+            },
+            ActivityTraceId.CreateFromString("1befc31e94b01d1a473f63a7905f6c9b"),
+            ActivitySpanId.CreateFromString("bb1111820570b80e"));
 
         var frFr = CultureInfo.GetCultureInfoByIetfLanguageTag("fr-FR");
         var testHelpers = new TestHelperNameResolver();