chore: Exception logging to include inner exceptions

libraries/src/AWS.Lambda.Powertools.Logging/Internal/Converters/ExceptionConverter.cs

@@ -57,39 +57,50 @@
     /// <param name="options">The JsonSerializer options.</param>
     public override void Write(Utf8JsonWriter writer, Exception value, JsonSerializerOptions options)
     {
-        var exceptionType = value.GetType();
-        var properties = ExceptionPropertyExtractor.ExtractProperties(value);
+        void WriteException(Utf8JsonWriter w, Exception ex)
+        {
+            var exceptionType = ex.GetType();
+            var properties = ExceptionPropertyExtractor.ExtractProperties(ex);
 
-        if (options.DefaultIgnoreCondition == JsonIgnoreCondition.WhenWritingNull)
-            properties = properties.Where(prop => prop.Value != null);
+            if (options.DefaultIgnoreCondition == JsonIgnoreCondition.WhenWritingNull)
+                properties = properties.Where(prop => prop.Value != null);
 
-        var props = properties.ToArray();
-        if (props.Length == 0)
-            return;
+            var props = properties.ToArray();
+            if (props.Length == 0)
+                return;
 
-        writer.WriteStartObject();
-        writer.WriteString(ApplyPropertyNamingPolicy("Type", options), exceptionType.FullName);
-
-        foreach (var prop in props)
-        {
-            switch (prop.Value)
+            w.WriteStartObject();
+            w.WriteString(ApplyPropertyNamingPolicy("Type", options), exceptionType.FullName);
+
+            foreach (var prop in props)
             {
-                case IntPtr intPtr:
-                    writer.WriteNumber(ApplyPropertyNamingPolicy(prop.Key, options), intPtr.ToInt64());
-                    break;
-                case UIntPtr uIntPtr:
-                    writer.WriteNumber(ApplyPropertyNamingPolicy(prop.Key, options), uIntPtr.ToUInt64());
-                    break;
-                case Type propType:
-                    writer.WriteString(ApplyPropertyNamingPolicy(prop.Key, options), propType.FullName);
-                    break;
-                case string propString:
-                    writer.WriteString(ApplyPropertyNamingPolicy(prop.Key, options), propString);
-                    break;
+                switch (prop.Value)
+                {
+                    case IntPtr intPtr:
+                        w.WriteNumber(ApplyPropertyNamingPolicy(prop.Key, options), intPtr.ToInt64());
+                        break;
+                    case UIntPtr uIntPtr:
+                        w.WriteNumber(ApplyPropertyNamingPolicy(prop.Key, options), uIntPtr.ToUInt64());
+                        break;
+                    case Type propType:
+                        w.WriteString(ApplyPropertyNamingPolicy(prop.Key, options), propType.FullName);
+                        break;
+                    case string propString:
+                        w.WriteString(ApplyPropertyNamingPolicy(prop.Key, options), propString);
+                        break;
+                }
             }
+
+            if (ex.InnerException != null)
+            {
+                w.WritePropertyName(ApplyPropertyNamingPolicy("InnerException", options));
+                WriteException(w, ex.InnerException);
+            }
+
+            w.WriteEndObject();
         }
 
-        writer.WriteEndObject();
+        WriteException(writer, value);
     }
 
     /// <summary>

libraries/src/AWS.Lambda.Powertools.Logging/Internal/Converters/ExceptionPropertyExtractor.cs

@@ -40,5 +40,6 @@ private static IEnumerable<KeyValuePair<string, object>> GetBaseExceptionPropert
         yield return new KeyValuePair<string, object>(nameof(Exception.Message), ex.Message);
         yield return new KeyValuePair<string, object>(nameof(Exception.Source), ex.Source);
         yield return new KeyValuePair<string, object>(nameof(Exception.StackTrace), ex.StackTrace);
+        yield return new KeyValuePair<string, object>(nameof(Exception.InnerException), ex.InnerException);
     }
 }

libraries/tests/AWS.Lambda.Powertools.Logging.Tests/PowertoolsLoggerTest.cs

@@ -1090,6 +1090,90 @@ public void Log_WhenException_LogsExceptionDetails()
                 s.Contains("\"exception\":{\"type\":\"System.InvalidOperationException\",\"message\":\"TestError\",\"source\":\"AWS.Lambda.Powertools.Logging.Tests\",\"stack_trace\":\"   at AWS.Lambda.Powertools.Logging.Tests.PowertoolsLoggerTest.Log_WhenException_LogsExceptionDetails()")
             ));
         }
+
+        [Fact]
+        public void Log_Inner_Exception()
+        {
+            // Arrange
+            var loggerName = Guid.NewGuid().ToString();
+            var service = Guid.NewGuid().ToString();
+            var error = new InvalidOperationException("Parent exception message",
+                new ArgumentNullException(nameof(service), "Very important inner exception message"));
+            var logLevel = LogLevel.Information;
+            var randomSampleRate = 0.5;
+
+            var configurations = Substitute.For<IPowertoolsConfigurations>();
+            configurations.Service.Returns(service);
+            configurations.LogLevel.Returns(logLevel.ToString());
+
+            var systemWrapper = Substitute.For<ISystemWrapper>();
+            systemWrapper.GetRandom().Returns(randomSampleRate);
+
+            var loggerConfiguration = new LoggerConfiguration
+            {
+                Service = null,
+                MinimumLevel = LogLevel.None
+            };
+
+            var provider = new LoggerProvider(loggerConfiguration, configurations, systemWrapper);
+            var logger = provider.CreateLogger(loggerName);
+
+            logger.LogError(
+                error, 
+                "Something went wrong and we logged an exception itself with an inner exception. This is a param {arg}",
+                12345);
+
+            // Assert
+            systemWrapper.Received(1).LogLine(Arg.Is<string>(s =>
+                s.Contains("\"exception\":{\"type\":\"" + error.GetType().FullName + "\",\"message\":\"" +
+                           error.Message + "\"")
+            ));
+
+            systemWrapper.Received(1).LogLine(Arg.Is<string>(s =>
+                s.Contains("\"level\":\"Error\",\"service\":\"" + service+ "\",\"name\":\"" + loggerName + "\",\"message\":\"Something went wrong and we logged an exception itself with an inner exception. This is a param 12345\",\"exception\":{\"type\":\"System.InvalidOperationException\",\"message\":\"Parent exception message\",\"inner_exception\":{\"type\":\"System.ArgumentNullException\",\"message\":\"Very important inner exception message (Parameter 'service')\"}}}")
+            ));
+        }
+
+        [Fact]
+        public void Log_Nested_Inner_Exception()
+        {
+            // Arrange
+            var loggerName = Guid.NewGuid().ToString();
+            var service = Guid.NewGuid().ToString();
+            var error = new InvalidOperationException("Parent exception message",
+                new ArgumentNullException(nameof(service),
+                    new Exception("Very important nested inner exception message")));
+
+            var logLevel = LogLevel.Information;
+            var randomSampleRate = 0.5;
+
+            var configurations = Substitute.For<IPowertoolsConfigurations>();
+            configurations.Service.Returns(service);
+            configurations.LogLevel.Returns(logLevel.ToString());
+
+            var systemWrapper = Substitute.For<ISystemWrapper>();
+            systemWrapper.GetRandom().Returns(randomSampleRate);
+
+            var loggerConfiguration = new LoggerConfiguration
+            {
+                Service = null,
+                MinimumLevel = LogLevel.None
+            };
+
+            var provider = new LoggerProvider(loggerConfiguration, configurations, systemWrapper);
+            var logger = provider.CreateLogger(loggerName);
+
+
+            logger.LogError(
+                error, 
+                "Something went wrong and we logged an exception itself with an inner exception. This is a param {arg}",
+                12345);
+
+            // Assert
+            systemWrapper.Received(1).LogLine(Arg.Is<string>(s =>
+                s.Contains("\"message\":\"Something went wrong and we logged an exception itself with an inner exception. This is a param 12345\",\"exception\":{\"type\":\"System.InvalidOperationException\",\"message\":\"Parent exception message\",\"inner_exception\":{\"type\":\"System.ArgumentNullException\",\"message\":\"service\",\"inner_exception\":{\"type\":\"System.Exception\",\"message\":\"Very important nested inner exception message\"}}}}")
+            ));
+        }
 
         [Fact]
         public void Log_WhenNestedException_LogsExceptionDetails()