// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

// @dart = 2.9

/// @assertion Stream<String> bind(Stream<List<int>> stream)
/// Transform the incoming stream's events.
///
/// Creates a new stream. When this stream is listened to, it will start
/// listening on stream, and generate events on the new stream based on the
/// events from stream.
///
/// Subscriptions on the returned stream should propagate pause state to the
/// subscription on stream.
/// @description Checks that this method transforms stream's events
/// @author sgrekhov@unipro.ru

import "dart:async";
import "dart:convert";
import "../../../Utils/expect.dart";

Future check(List<int> codeUnits) async {
  Base64Encoder encoder = new Base64Encoder();
  int counter = 0;

  await for (String event in encoder.bind(new Stream.fromIterable([codeUnits]))) {
    String data = base64.encode(codeUnits);
    Expect.equals(data, event);
    counter++;
  }
}

main() {
  asyncStart();
  Future.wait([
    check([]),
    check("S".codeUnits),
    check("So".codeUnits),
    check("Som".codeUnits),
  ]).then(
      (_) => asyncEnd()
  );
}