NoSuchMethodError (NoSuchMethodError: Class '[AnyType]' has no instance getter 'toJSON'.

[mrasityilmaz]

NoSuchMethodError: Class '_Map<String, Object>' has no instance getter 'toJson' in socket.io usage with EVENT type packets

Description

I am encountering a NoSuchMethodError with the following details:
This error occurs when I receive packets of type EVENT while using socket_io_client. To resolve this, I updated the package version from 3.0.0-beta.2 to 3.0.2 as I saw a similar issue addressed in socket_io_common. However, the issue persists in the latest version as well.

The problem seems to be related to a missing toJson method in the Map implementation. The issue likely stems from how packets are being handled or parsed within the socket library.

Steps to Reproduce

1. Use the socket_io_client package version 3.0.2.
2. Establish a socket connection to a server.
3. Receive a packet of type EVENT.
4. Observe the following error in the logs:

NoSuchMethodError: Class ‘_Map<String, Object>’ has no instance getter ‘toJson’.
Receiver: _Map
Tried calling: toJson
---
NoSuchMethodError (NoSuchMethodError: Class '_Map<String, Object>' has no instance getter 'toJson'.
Receiver: _Map len:4
Tried calling: toJson)
---
NoSuchMethodError (NoSuchMethodError: Class 'int' has no instance getter 'toJSON'.
Receiver: 2
Tried calling: toJSON)
---
NoSuchMethodError (NoSuchMethodError: Class 'String' has no instance getter 'toJSON'.
Receiver: "exitRoom"
Tried calling: toJSON)
---
NoSuchMethodError (NoSuchMethodError: Class 'List<dynamic>' has no instance getter 'toJSON'.
Receiver: Instance(length:2) of '_GrowableList'
Tried calling: toJSON)

Environment

• Package: socket_io_client 3.0.2
• Dart/Flutter version: 3.5.4 - Dart SDK / 3.24.4 - Flutter SDK
• Platform: IOS

Expected Behavior

The library should correctly handle or parse EVENT type packets without throwing a NoSuchMethodError. Ideally, any _Map object should be deserialized properly or handled internally.

Actual Behavior

The application throws a NoSuchMethodError when a toJson method is called on _Map<String, Object> during the handling of an EVENT type packet.

Attachments

• A screenshot of the error is attached.

Example Code Snippet

socket.emit('eventName','StringValue');

[jumperchen]

The implementation should ignore this error: is_binary.dart. However, I don't know why Flutter throws that error. A few weeks ago, a user encountered a similar error, and after cleaning their Flutter environment, the error disappeared.