Even using a Sync Stream Controller + Buffering an event, the StraemBuilder will print "No Data" then "Has Data"

SyncStreamController + StreamBuilder

import 'dart:async';

import 'package:flutter/material.dart';

void main() => runApp(new MyApp());

class MyApp extends StatefulWidget {
  @override
  MyAppState createState() {
    return new MyAppState();
  }
}

class MyAppState extends State<MyApp> {
  final controller = StreamController<String>(sync: true)..add("Hello");

  @override
  void dispose() {
    controller.close();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new MyHomePage(
        title: 'Flutter Demo Home Page',
        stream: controller.stream,
      ),
    );
  }
}

class MyHomePage extends StatelessWidget {
  final String title;
  final Stream<String> stream;

  const MyHomePage({Key key, this.title, this.stream}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(title),
      ),
      body: StreamBuilder(
          stream: stream,
          builder: (context, snapshot) {
            print("Has Data? ${snapshot.hasData}");

            return Container();
          }),
    );
  }
}