LibTest/io/RandomAccessFile/writeByteSync_A01_t02.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.

/// @assertion int writeByteSync(int value)
/// Synchronously writes a single byte to the file. Returns the number of bytes
/// successfully written.
///
/// Throws a FileSystemException if the operation fails.
///
/// @description Checks that method writeByteSync throws a FileSystemException if
/// the operation fails.
/// @author ngl@unipro.ru

import "dart:async";
import "dart:io";
import "../../../Utils/expect.dart";
import "../file_utils.dart";

main() {
  File file = getTempFileSync();
  asyncStart();
  Future<RandomAccessFile> raFile = file.open(mode: FileMode.write);
  raFile.then((RandomAccessFile rf) {
    Expect.equals(0, file.lengthSync());
    var n = rf.writeByteSync(0);
    Expect.isTrue(n is int);
    Expect.runtimeIsType<int>(n);
    Expect.equals(1, n);
    Expect.equals(1, rf.lengthSync());
    rf.closeSync();
    try {
      n = rf.writeByteSync(1);
      Expect.fail("should not be here.");
    } on Exception catch (e) {
      Expect.isTrue(e is FileSystemException);
    }
    asyncEnd();
  }).whenComplete(() {
    file.deleteSync();
  });
}