Add HttpContext extension method for graceful correlation ID retrieval

README.md

@@ -94,6 +94,26 @@ or
   }
 }
 ```
+
+#### Retrieving Correlation ID
+You can easily retrieve the correlation ID from `HttpContext` using the `GetCorrelationId()` extension method:
+
+```csharp
+public void SomeControllerAction()
+{
+    // This will return the correlation ID that was enriched by the CorrelationIdEnricher
+    var correlationId = HttpContext.GetCorrelationId();
+
+    // You can use this for error reporting, tracing, etc.
+    if (!string.IsNullOrEmpty(correlationId))
+    {
+        // Show correlation ID to user for error reporting
+        // or use it for additional logging/tracing
+    }
+}
+```
+
+This eliminates the need for manual casting and provides a clean API for accessing correlation IDs.
 ### RequestHeader
 You can use multiple `WithRequestHeader` to log different request headers. `WithRequestHeader` accepts two parameters; The first parameter `headerName` is the header name to log 
 and the second parameter is `propertyName` which is the log property name.

src/Serilog.Enrichers.ClientInfo/Enrichers/CorrelationIdEnricher.cs

@@ -9,6 +9,7 @@ namespace Serilog.Enrichers;
 public class CorrelationIdEnricher : ILogEventEnricher
 {
     private const string CorrelationIdItemKey = "Serilog_CorrelationId";
+    private const string CorrelationIdValueKey = "Serilog_CorrelationId_Value";
     private const string PropertyName = "CorrelationId";
     private readonly string _headerKey;
     private readonly bool _addValueIfHeaderAbsence;
@@ -47,6 +48,14 @@ public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
         if (httpContext.Items[CorrelationIdItemKey] is LogEventProperty logEventProperty)
         {
             logEvent.AddPropertyIfAbsent(logEventProperty);
+
+            // Ensure the string value is also available if not already stored
+            if (!httpContext.Items.ContainsKey(CorrelationIdValueKey))
+            {
+                var correlationIdValue = ((ScalarValue)logEventProperty.Value).Value as string;
+                httpContext.Items.Add(CorrelationIdValueKey, correlationIdValue);
+            }
+
             return;
         }
 
@@ -76,5 +85,6 @@ public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
         logEvent.AddOrUpdateProperty(correlationIdProperty);
 
         httpContext.Items.Add(CorrelationIdItemKey, correlationIdProperty);
+        httpContext.Items.Add(CorrelationIdValueKey, correlationId);
     }
 }

src/Serilog.Enrichers.ClientInfo/Extensions/HttpContextExtensions.cs

@@ -0,0 +1,21 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Serilog.Enrichers;
+
+/// <summary>
+///   Extension methods for <see cref="HttpContext"/> to access enriched values.
+/// </summary>
+public static class HttpContextExtensions
+{
+    private const string CorrelationIdValueKey = "Serilog_CorrelationId_Value";
+
+    /// <summary>
+    ///   Retrieves the correlation ID value from the current HTTP context.
+    /// </summary>
+    /// <param name="httpContext">The HTTP context.</param>
+    /// <returns>The correlation ID as a string, or null if not available.</returns>
+    public static string GetCorrelationId(this HttpContext httpContext)
+    {
+        return httpContext?.Items[CorrelationIdValueKey] as string;
+    }
+}

src/Serilog.Enrichers.ClientInfo/Serilog.Enrichers.ClientInfo.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
 	<PropertyGroup>
-		<TargetFrameworks>net8.0;net9.0</TargetFrameworks>
+		<TargetFrameworks>net8.0</TargetFrameworks>
 		<AssemblyName>Serilog.Enrichers.ClientInfo</AssemblyName>
     <RootNamespace>Serilog</RootNamespace>
 	  <LangVersion>latest</LangVersion>

test/Serilog.Enrichers.ClientInfo.Tests/CorrelationIdEnricherTests.cs

@@ -1,5 +1,6 @@
 using Microsoft.AspNetCore.Http;
 using NSubstitute;
+using Serilog.Enrichers;
 using Serilog.Events;
 using System;
 using Xunit;
@@ -170,4 +171,145 @@ public void WithClientIp_ThenLoggerIsCalled_ShouldNotThrowException()
         // Assert
         Assert.Null(exception);
     }
+
+    [Fact]
+    public void GetCorrelationId_WhenHttpRequestContainCorrelationHeader_ShouldReturnCorrelationIdFromHttpContext()
+    {
+        // Arrange
+        var correlationId = Guid.NewGuid().ToString();
+        _contextAccessor.HttpContext!.Request!.Headers[HeaderKey] = correlationId;
+        var correlationIdEnricher = new CorrelationIdEnricher(HeaderKey, false, _contextAccessor);
+
+        LogEvent evt = null;
+        var log = new LoggerConfiguration()
+            .Enrich.With(correlationIdEnricher)
+            .WriteTo.Sink(new DelegatingSink(e => evt = e))
+            .CreateLogger();
+
+        // Act
+        log.Information(@"Has a correlation id.");
+        var retrievedCorrelationId = _contextAccessor.HttpContext!.GetCorrelationId();
+
+        // Assert
+        Assert.NotNull(evt);
+        Assert.Equal(correlationId, retrievedCorrelationId);
+    }
+
+    [Fact]
+    public void GetCorrelationId_WhenHttpRequestNotContainCorrelationHeaderAndAddDefaultValueIsTrue_ShouldReturnGeneratedCorrelationIdFromHttpContext()
+    {
+        // Arrange
+        var correlationIdEnricher = new CorrelationIdEnricher(HeaderKey, true, _contextAccessor);
+
+        LogEvent evt = null;
+        var log = new LoggerConfiguration()
+            .Enrich.With(correlationIdEnricher)
+            .WriteTo.Sink(new DelegatingSink(e => evt = e))
+            .CreateLogger();
+
+        // Act
+        log.Information(@"Has a correlation id.");
+        var retrievedCorrelationId = _contextAccessor.HttpContext!.GetCorrelationId();
+
+        // Assert
+        Assert.NotNull(evt);
+        Assert.NotNull(retrievedCorrelationId);
+        Assert.NotEmpty(retrievedCorrelationId);
+        // Verify it's a valid GUID format
+        Assert.True(Guid.TryParse(retrievedCorrelationId, out _));
+    }
+
+    [Fact]
+    public void GetCorrelationId_WhenHttpRequestNotContainCorrelationHeaderAndAddDefaultValueIsFalse_ShouldReturnNullFromHttpContext()
+    {
+        // Arrange
+        var correlationIdEnricher = new CorrelationIdEnricher(HeaderKey, false, _contextAccessor);
+
+        LogEvent evt = null;
+        var log = new LoggerConfiguration()
+            .Enrich.With(correlationIdEnricher)
+            .WriteTo.Sink(new DelegatingSink(e => evt = e))
+            .CreateLogger();
+
+        // Act
+        log.Information(@"Has a correlation id.");
+        var retrievedCorrelationId = _contextAccessor.HttpContext!.GetCorrelationId();
+
+        // Assert
+        Assert.NotNull(evt);
+        Assert.Null(retrievedCorrelationId);
+    }
+
+    [Fact]
+    public void GetCorrelationId_WhenCalledMultipleTimes_ShouldReturnSameCorrelationId()
+    {
+        // Arrange
+        var correlationId = Guid.NewGuid().ToString();
+        _contextAccessor.HttpContext!.Request!.Headers[HeaderKey] = correlationId;
+        var correlationIdEnricher = new CorrelationIdEnricher(HeaderKey, false, _contextAccessor);
+
+        var log = new LoggerConfiguration()
+            .Enrich.With(correlationIdEnricher)
+            .WriteTo.Sink(new DelegatingSink(_ => { }))
+            .CreateLogger();
+
+        // Act
+        log.Information(@"First log message.");
+        var firstRetrieval = _contextAccessor.HttpContext!.GetCorrelationId();
+
+        log.Information(@"Second log message.");
+        var secondRetrieval = _contextAccessor.HttpContext!.GetCorrelationId();
+
+        // Assert
+        Assert.Equal(correlationId, firstRetrieval);
+        Assert.Equal(correlationId, secondRetrieval);
+        Assert.Equal(firstRetrieval, secondRetrieval);
+    }
+
+    [Fact]
+    public void GetCorrelationId_WhenHttpContextIsNull_ShouldReturnNull()
+    {
+        // Arrange & Act
+        var result = HttpContextExtensions.GetCorrelationId(null);
+
+        // Assert
+        Assert.Null(result);
+    }
+
+    [Fact]
+    public void EnrichLogWithCorrelationId_BackwardCompatibility_OldRetrievalMethodShouldStillWork()
+    {
+        // Arrange
+        var correlationId = Guid.NewGuid().ToString();
+        _contextAccessor.HttpContext!.Request!.Headers[HeaderKey] = correlationId;
+        var correlationIdEnricher = new CorrelationIdEnricher(HeaderKey, false, _contextAccessor);
+
+        LogEvent evt = null;
+        var log = new LoggerConfiguration()
+            .Enrich.With(correlationIdEnricher)
+            .WriteTo.Sink(new DelegatingSink(e => evt = e))
+            .CreateLogger();
+
+        // Act
+        log.Information(@"Has a correlation id.");
+
+        // Test that the old way (hacky way) still works
+        var httpContext = _contextAccessor.HttpContext!;
+        string retrievedCorrelationIdOldWay = null;
+
+        if (httpContext.Items.TryGetValue("Serilog_CorrelationId", out var correlationIdItem) &&
+            correlationIdItem is LogEventProperty { Name: "CorrelationId" } correlationIdProperty)
+        {
+            retrievedCorrelationIdOldWay = ((ScalarValue)correlationIdProperty.Value).Value as string;
+        }
+
+        // Test that the new way also works
+        var retrievedCorrelationIdNewWay = httpContext.GetCorrelationId();
+
+        // Assert
+        Assert.NotNull(evt);
+        Assert.Equal(correlationId, retrievedCorrelationIdOldWay);
+        Assert.Equal(correlationId, retrievedCorrelationIdNewWay);
+        Assert.Equal(retrievedCorrelationIdOldWay, retrievedCorrelationIdNewWay);
+    }
 }

test/Serilog.Enrichers.ClientInfo.Tests/Serilog.Enrichers.ClientInfo.Tests.csproj

@@ -1,13 +1,13 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="9.0.6" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
     <PackageReference Include="nsubstitute" Version="5.1.0" />
     <PackageReference Include="Serilog.AspNetCore" Version="8.0.1" />
     <PackageReference Include="xunit" Version="2.9.0" />