onDone callback not working when connection closes

[MrChausson]

Hello there,

I have been using this library and it worked fine but I have one problem with it: when the server closes the connection (Which I have checked is done right and works on postman for example), I cannot figure out how to detect it.

So I have made a EventStreamManager class that handles the stream because I needed a broadcast stream (then I figured out I could maybe do it simpler but that's not the point).

I can get events and all but nothing ever passes in the onDone callback function. I have tried everything but I cannot figure out how to make it work.

Has someone ever made it work ?

EventStreamManager.dart

import 'dart:async';
import 'package:echo_app/api/api_client.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_client_sse/flutter_client_sse.dart';

class EventStreamManager {
  final ApiClient _apiClient;
  StreamController<SSEModel>? _streamController;

  EventStreamManager(this._apiClient);

  Stream<SSEModel> get stream => _streamController!.stream;

  Future<void> startListeningForEvents(String sessionId) async {
    _streamController = StreamController<SSEModel>.broadcast();

    Stream<SSEModel> eventStream =
        await _apiClient.startListeningForEvents(sessionId);
    eventStream.listen((event) {
      if (!_streamController!.isClosed) {
        _streamController!.sink.add(event);
      }
    }, onDone: () {
      if (kDebugMode) {
        print('SSE closed');
      }
      _streamController!.close();
    }, onError: (error) {
      _streamController!.addError(error);
    });
  }

  void stopListeningForEvents() {
    _apiClient.stopListeningForEvents();
    _streamController?.close();
    _streamController = null;
  }
}

ApiClient.startListeningForEvents function:

  Future<Stream<SSEModel>> startListeningForEvents(String sessionId) async {
    var token = await getAccessToken();
    return SSEClient.subscribeToSSE(
        method: SSERequestType.GET,
        url: '$baseUrl/sessions/$sessionId',
        header: {
          'Content-Type': 'application/json',
          'Authorization': 'Bearer $token',
        });
  }