Features

• emit an Error object upon middleware error (54bf4a4)
• serve msgpack bundle (aa7574f)

Links:

• Milestone: 3.0.0
• Diff: https://github.com/socketio/socket.io/compare/3.0.0-rc3...3.0.0-rc4
• Client release: 3.0.0-rc4
• engine.io version: ~4.0.0
• ws version: ^7.1.2