Improve logging messages

src/Polly.Extensions/Telemetry/Log.cs

@@ -12,7 +12,7 @@ internal static partial class Log
         EventId = 0,
         Message = "Resilience event occurred. " +
                 "EventName: '{EventName}', " +
-                "Source: '{BuilderName}[{BuilderInstance}]/{StrategyName}', " +
+                "Source: '{BuilderName}/{BuilderInstance}/{StrategyName}', " +
                 "Operation Key: '{OperationKey}', " +
                 "Result: '{Result}'",
         EventName = "ResilienceEvent")]
@@ -31,7 +31,7 @@ public static partial void ResilienceEvent(
         1,
         LogLevel.Debug,
         "Resilience strategy executing. " +
-        "Source: '{BuilderName}[{BuilderInstance}]', " +
+        "Source: '{BuilderName}/{BuilderInstance}', " +
         "Operation Key: '{OperationKey}', " +
         "Result Type: '{ResultType}'",
         EventName = "StrategyExecuting")]
@@ -45,7 +45,7 @@ public static partial void ExecutingStrategy(
     [LoggerMessage(
         EventId = 2,
         Message = "Resilience strategy executed. " +
-            "Source: '{BuilderName}[{BuilderInstance}]', " +
+            "Source: '{BuilderName}/{BuilderInstance}', " +
             "Operation Key: '{OperationKey}', " +
             "Result Type: '{ResultType}', " +
             "Result: '{Result}', " +
@@ -67,7 +67,7 @@ public static partial void StrategyExecuted(
     [LoggerMessage(
         EventId = 3,
         Message = "Execution attempt. " +
-                "Source: '{BuilderName}[{BuilderInstance}]/{StrategyName}', " +
+                "Source: '{BuilderName}/{BuilderInstance}/{StrategyName}', " +
                 "Operation Key: '{OperationKey}', " +
                 "Result: '{Result}', " +
                 "Handled: '{Handled}', " +

src/Polly.Extensions/Telemetry/ResilienceTelemetryDiagnosticSource.cs

@@ -115,9 +115,9 @@ private void LogEvent(TelemetryEventArguments args)
                 Log.ExecutionAttempt(
                     _logger,
                     level,
-                    args.Source.BuilderName,
-                    args.Source.BuilderInstanceName,
-                    args.Source.StrategyName,
+                    args.Source.BuilderName.GetValueOrPlaceholder(),
+                    args.Source.BuilderInstanceName.GetValueOrPlaceholder(),
+                    args.Source.StrategyName.GetValueOrPlaceholder(),
                     args.Context.OperationKey,
                     result,
                     executionAttempt.Handled,
@@ -132,9 +132,9 @@ private void LogEvent(TelemetryEventArguments args)
                 _logger,
                 level,
                 args.Event.EventName,
-                args.Source.BuilderName,
-                args.Source.BuilderInstanceName,
-                args.Source.StrategyName,
+                args.Source.BuilderName.GetValueOrPlaceholder(),
+                args.Source.BuilderInstanceName.GetValueOrPlaceholder(),
+                args.Source.StrategyName.GetValueOrPlaceholder(),
                 args.Context.OperationKey,
                 result,
                 args.Outcome?.Exception);

src/Polly.Extensions/Telemetry/TelemetryResilienceStrategy.cs

@@ -6,8 +6,8 @@ namespace Polly.Extensions.Telemetry;
 internal sealed class TelemetryResilienceStrategy : ResilienceStrategy
 {
     private readonly TimeProvider _timeProvider;
-    private readonly string? _builderName;
-    private readonly string? _builderInstance;
+    private readonly string _builderName;
+    private readonly string _builderInstance;
     private readonly List<Action<EnrichmentContext>> _enrichers;
     private readonly ILogger _logger;
     private readonly Func<ResilienceContext, object?, object?> _resultFormatter;
@@ -32,8 +32,8 @@ public TelemetryResilienceStrategy(
         List<Action<EnrichmentContext>> enrichers)
     {
         _timeProvider = timeProvider;
-        _builderName = builderName;
-        _builderInstance = builderInstance;
+        _builderName = builderName.GetValueOrPlaceholder();
+        _builderInstance = builderInstance.GetValueOrPlaceholder();
         _resultFormatter = resultFormatter;
         _enrichers = enrichers;
         _logger = loggerFactory.CreateLogger(TelemetryUtil.PollyDiagnosticSource);

src/Polly.Extensions/Telemetry/TelemetryUtil.cs

@@ -15,6 +15,8 @@ internal static class TelemetryUtil
 
     internal const string PollyDiagnosticSource = "Polly";
 
+    public static string GetValueOrPlaceholder(this string? value) => value ?? "(null)";
+
     public static object AsBoxedBool(this bool value) => value switch
     {
         true => True,

test/Polly.Extensions.Tests/Telemetry/ResilienceTelemetryDiagnosticSourceTests.cs

@@ -72,11 +72,11 @@ public void WriteEvent_LoggingWithOutcome_Ok(bool noOutcome)
 
         if (noOutcome)
         {
-            messages[0].Message.Should().Be("Resilience event occurred. EventName: 'my-event', Source: 'my-builder[builder-instance]/my-strategy', Operation Key: 'op-key', Result: ''");
+            messages[0].Message.Should().Be("Resilience event occurred. EventName: 'my-event', Source: 'my-builder/builder-instance/my-strategy', Operation Key: 'op-key', Result: ''");
         }
         else
         {
-            messages[0].Message.Should().Be("Resilience event occurred. EventName: 'my-event', Source: 'my-builder[builder-instance]/my-strategy', Operation Key: 'op-key', Result: '200'");
+            messages[0].Message.Should().Be("Resilience event occurred. EventName: 'my-event', Source: 'my-builder/builder-instance/my-strategy', Operation Key: 'op-key', Result: '200'");
         }
     }
 
@@ -99,11 +99,11 @@ public void WriteEvent_LoggingWithException_Ok(bool noOutcome)
 
         if (noOutcome)
         {
-            messages[0].Message.Should().Be("Resilience event occurred. EventName: 'my-event', Source: 'my-builder[builder-instance]/my-strategy', Operation Key: 'op-key', Result: ''");
+            messages[0].Message.Should().Be("Resilience event occurred. EventName: 'my-event', Source: 'my-builder/builder-instance/my-strategy', Operation Key: 'op-key', Result: ''");
         }
         else
         {
-            messages[0].Message.Should().Be("Resilience event occurred. EventName: 'my-event', Source: 'my-builder[builder-instance]/my-strategy', Operation Key: 'op-key', Result: 'Dummy message.'");
+            messages[0].Message.Should().Be("Resilience event occurred. EventName: 'my-event', Source: 'my-builder/builder-instance/my-strategy', Operation Key: 'op-key', Result: 'Dummy message.'");
         }
     }
 
@@ -115,7 +115,7 @@ public void WriteEvent_LoggingWithoutInstanceName_Ok()
 
         var messages = _logger.GetRecords(new EventId(0, "ResilienceEvent")).ToList();
 
-        messages[0].Message.Should().Be("Resilience event occurred. EventName: 'my-event', Source: 'my-builder[]/my-strategy', Operation Key: 'op-key', Result: ''");
+        messages[0].Message.Should().Be("Resilience event occurred. EventName: 'my-event', Source: 'my-builder/(null)/my-strategy', Operation Key: 'op-key', Result: ''");
     }
 
     [InlineData(ResilienceEventSeverity.Error, LogLevel.Error)]
@@ -150,7 +150,7 @@ public void WriteExecutionAttempt_LoggingWithException_Ok()
         var messages = _logger.GetRecords(new EventId(3, "ExecutionAttempt")).ToList();
         messages.Should().HaveCount(1);
 
-        messages[0].Message.Should().Be("Execution attempt. Source: 'my-builder[builder-instance]/my-strategy', Operation Key: 'op-key', Result: 'Dummy message.', Handled: 'True', Attempt: '4', Execution Time: '123'");
+        messages[0].Message.Should().Be("Execution attempt. Source: 'my-builder/builder-instance/my-strategy', Operation Key: 'op-key', Result: 'Dummy message.', Handled: 'True', Attempt: '4', Execution Time: '123'");
     }
 
     [InlineData(true, true)]
@@ -170,11 +170,11 @@ public void WriteExecutionAttempt_LoggingWithOutcome_Ok(bool noOutcome, bool han
         if (noOutcome)
         {
             string resultString = string.Empty;
-            messages[0].Message.Should().Be($"Execution attempt. Source: 'my-builder[builder-instance]/my-strategy', Operation Key: 'op-key', Result: '{resultString}', Handled: '{handled}', Attempt: '4', Execution Time: '123'");
+            messages[0].Message.Should().Be($"Execution attempt. Source: 'my-builder/builder-instance/my-strategy', Operation Key: 'op-key', Result: '{resultString}', Handled: '{handled}', Attempt: '4', Execution Time: '123'");
         }
         else
         {
-            messages[0].Message.Should().Be($"Execution attempt. Source: 'my-builder[builder-instance]/my-strategy', Operation Key: 'op-key', Result: '200', Handled: '{handled}', Attempt: '4', Execution Time: '123'");
+            messages[0].Message.Should().Be($"Execution attempt. Source: 'my-builder/builder-instance/my-strategy', Operation Key: 'op-key', Result: '200', Handled: '{handled}', Attempt: '4', Execution Time: '123'");
         }
 
         messages[0].LogLevel.Should().Be(LogLevel.Warning);

test/Polly.Extensions.Tests/Telemetry/TelemetryResilienceStrategyTests.cs

@@ -50,10 +50,10 @@ public void Execute_EnsureLogged(bool healthy)
 
         var messages = _logger.GetRecords(new EventId(1, "StrategyExecuting")).ToList();
         messages.Should().HaveCount(1);
-        messages[0].Message.Should().Be("Resilience strategy executing. Source: 'my-builder[my-instance]', Operation Key: 'op-key', Result Type: 'void'");
+        messages[0].Message.Should().Be("Resilience strategy executing. Source: 'my-builder/my-instance', Operation Key: 'op-key', Result Type: 'void'");
         messages = _logger.GetRecords(new EventId(2, "StrategyExecuted")).ToList();
         messages.Should().HaveCount(1);
-        messages[0].Message.Should().Match($"Resilience strategy executed. Source: 'my-builder[my-instance]', Operation Key: 'op-key', Result Type: 'void', Result: 'void', Execution Health: '{healthString}', Execution Time: *ms");
+        messages[0].Message.Should().Match($"Resilience strategy executed. Source: 'my-builder/my-instance', Operation Key: 'op-key', Result Type: 'void', Result: 'void', Execution Health: '{healthString}', Execution Time: *ms");
         messages[0].LogLevel.Should().Be(healthy ? LogLevel.Debug : LogLevel.Warning);
 
         // verify reported state
@@ -78,11 +78,11 @@ public void Execute_WithException_EnsureLogged()
 
         var messages = _logger.GetRecords(new EventId(1, "StrategyExecuting")).ToList();
         messages.Should().HaveCount(1);
-        messages[0].Message.Should().Be("Resilience strategy executing. Source: 'my-builder[my-instance]', Operation Key: 'op-key', Result Type: 'void'");
+        messages[0].Message.Should().Be("Resilience strategy executing. Source: 'my-builder/my-instance', Operation Key: 'op-key', Result Type: 'void'");
 
         messages = _logger.GetRecords(new EventId(2, "StrategyExecuted")).ToList();
         messages.Should().HaveCount(1);
-        messages[0].Message.Should().Match($"Resilience strategy executed. Source: 'my-builder[my-instance]', Operation Key: 'op-key', Result Type: 'void', Result: 'Dummy message.', Execution Health: 'Healthy', Execution Time: *ms");
+        messages[0].Message.Should().Match($"Resilience strategy executed. Source: 'my-builder/my-instance', Operation Key: 'op-key', Result Type: 'void', Result: 'Dummy message.', Execution Health: 'Healthy', Execution Time: *ms");
         messages[0].Exception.Should().BeOfType<InvalidOperationException>();
     }
 

test/Polly.Extensions.Tests/Utils/TelemetryUtilTests.cs

@@ -25,4 +25,11 @@ public void AsBoxedInt_Ok()
         (-1).AsBoxedInt().Should().NotBeSameAs((-1).AsBoxedInt());
         100.AsBoxedInt().Should().NotBeSameAs(100.AsBoxedInt());
     }
+
+    [Fact]
+    public void GetValueOrPlaceholder_Ok()
+    {
+        TelemetryUtil.GetValueOrPlaceholder("dummy").Should().Be("dummy");
+        TelemetryUtil.GetValueOrPlaceholder(null).Should().Be("(null)");
+    }
 }