LibTest/convert/StringConversionSink/asStringSink_A02_t01.dart

// 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 ClosableStringSink asStringSink()
/// ...
/// If used, this method must be the first and only call to this. It invalidates
/// this. All further operations must be performed on the result.
/// @description Checks that this method invalidates this and all further
/// operations must be performed on the result.
/// @issue 29353
/// @author sgrekhov@unipro.ru

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

main() {
  bool called = false;
  
  var outSink = new ByteConversionSink.withCallback((accumulated) {
    called = true;
    Expect.listEquals(utf8.encode("12"), accumulated);
  });

  StringConversionSink inSink = utf8.encoder.startChunkedConversion(outSink);
  inSink.add("1");

  ClosableStringSink css = inSink.asStringSink();
  css.write("2");
  inSink.add("3");
  css.close();
  Expect.isTrue(called);
  inSink.add("4");
  inSink.close();
}