Bug: Enum logging throws NotSupportedException and empty log entry when running under .net8

[nCubed]

Expected Behaviour

When logging an Enum, the value of the enum should be logged.

Current Behaviour

Of note: this only occurs with the .net8 runtime; not the .net6 runtime.

v1.6 introduced a change in behavior when logging an Enum. Depending on the Enum, the logged value is either an empty json object or will throw a NotSupportedException.

Using the code snippet provided, the logging output has the following behavior.

v1.5.1 (and prior)

• logging has no errors and logs the values

{
    "timestamp": "<snip>",
    "level": "Information",
    "service": "<snip>",
    "name": "<snip>",
    "message": 5
}

{
    "timestamp": "<snip>",
    "level": "Information",
    "service": "<snip>",
    "name": "<snip>",
    "message": {
        "r": 199,
        "g": 21,
        "b": 133,
        "a": 255,
        "is_known_color": true,
        "is_empty": false,
        "is_named_color": true,
        "is_system_color": false,
        "name": "MediumVioletRed"
    }
}

v1.6.0

• custom enum is en empty json object
• .net enum (and 3rd party dll enum) cause an exception

{
    "timestamp": "<snip>",
    "level": "Information",
    "service": "<snip>",
    "name": "<snip>",
    "message": {}
}

Exception for 2nd log entry:

System.NotSupportedException
  HResult=0x80131515
  Message=JsonTypeInfo metadata for type 'System.Drawing.Color' was not provided by TypeInfoResolver of type '[AWS.Lambda.Powertools.Logging.Serializers.PowertoolsLoggingSerializationContext]'. If using source generation, ensure that all root types passed to the serializer have been annotated with 'JsonSerializableAttribute', along with any types that might be serialized polymorphically. The unsupported member type is located on type 'System.Object'. Path: $.
  Source=System.Text.Json
  StackTrace:
   at System.Text.Json.ThrowHelper.ThrowNotSupportedException(WriteStack& state, NotSupportedException ex)
   at System.Text.Json.Serialization.JsonConverter`1.WriteCore(Utf8JsonWriter writer, T& value, JsonSerializerOptions options, WriteStack& state)
   at System.Text.Json.Serialization.Metadata.JsonTypeInfo`1.Serialize(Utf8JsonWriter writer, T& rootValue, Object rootValueBoxed)
   at System.Text.Json.Serialization.Metadata.JsonTypeInfo`1.SerializeAsObject(Utf8JsonWriter writer, Object rootValue)
   at System.Text.Json.Serialization.Metadata.JsonTypeInfo`1.Serialize(Utf8JsonWriter writer, T& rootValue, Object rootValueBoxed)
   at System.Text.Json.Serialization.Metadata.JsonTypeInfo`1.SerializeAsObject(Utf8JsonWriter writer, Object rootValue)
   at System.Text.Json.JsonSerializer.WriteStringAsObject(Object value, JsonTypeInfo jsonTypeInfo)
   at AWS.Lambda.Powertools.Logging.Serializers.PowertoolsLoggingSerializer.Serialize(Object value, Type inputType)
   at AWS.Lambda.Powertools.Logging.Internal.PowertoolsLogger.Log[TState](LogLevel logLevel, EventId eventId, TState state, Exception exception, Func`3 formatter)
   at Microsoft.Extensions.Logging.LoggerExtensions.Log(ILogger logger, LogLevel logLevel, EventId eventId, Exception exception, String message, Object[] args)
   at Microsoft.Extensions.Logging.LoggerExtensions.Log(ILogger logger, LogLevel logLevel, String message, Object[] args)
   at Microsoft.Extensions.Logging.LoggerExtensions.LogInformation(ILogger logger, String message, Object[] args)
   at AWS.Lambda.Powertools.Logging.LoggerExtensions.LogInformation(ILogger logger, Object message)
   at AWS.Lambda.Powertools.Logging.Logger.LogInformation(Object message)
   at Program.<Main>$(String[] args) in C:\.dev\tmp\AwsPowertoolsLogging\Console02\Program.cs:line 11

  This exception was originally thrown at this call stack:
    [External Code]

Inner Exception 1:
NotSupportedException: JsonTypeInfo metadata for type 'System.Drawing.Color' was not provided by TypeInfoResolver of type '[AWS.Lambda.Powertools.Logging.Serializers.PowertoolsLoggingSerializationContext]'. If using source generation, ensure that all root types passed to the serializer have been annotated with 'JsonSerializableAttribute', along with any types that might be serialized polymorphically.

Code snippet

using System.Drawing;
using AWS.Lambda.Powertools.Logging;

Logger.LogInformation(Pet.Lizard);
Logger.LogInformation(Color.MediumVioletRed);

public enum Pet
{
    Cat = 1,
    Dog = 3,
    Lizard = 5
}

Possible Solution

n/a

Steps to Reproduce

• Use the .net8 runtime
• Use the code snippet provided with v1.5.1 and then 1.6.0

Powertools for AWS Lambda (.NET) version

v1.6.0

AWS Lambda function runtime

dotnet6

Debugging logs

No response

[hjgraca]

Hi @nCubed thanks for opening the issue. and I will be looking at it shortly
Question, is this an AOT Lambda?

[nCubed]

Good question @hjgraca - this is not an AOT Lambda.

edit: In reading through the release notes, I was wondering if AOT may have been the underlying issue for the logger.

[hjgraca]

I asked because the error is very AOT, because of source generation.
Can you do another test, instead of an enum, can you create a simple class with one property and instanciate it and pass it to the logger to see if it complains about that type not being resolved (JsonTypeInfoResolver error).
I will do some tests on my side as well.

Edit: I was able to reproduce the enum error

[nCubed]

@hjgraca We discovered this issue when upgrading our lambdas to .net8. We have some startup unit tests that perform some logging w/ some complex objects (classes w/ nested child classes); the enum broke the logging; removing the enum and all was fine, so standard class/properties are looking good still. It's just the enum.

Thanks for taking a look so quickly. LMK if I can help.

[nCubed]

p.s. the issue UI has a dropdown for "AWS Lambda function runtime"; the only option is .net6. Can your team add .net8 as an option?

[hjgraca]

@nCubed
Fix is on the way #657
Thank you for reporting and helping me diagnose the issue.
I am planing on releasing v1.6.1 in a few moments.