LibTest/io/File/writeAsString_A03_t08.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 Future<File> writeAsString(
///  String contents, {
///  FileMode mode: FileMode.write,
///  Encoding encoding: utf8,
///  bool flush: false
///  })
/// Write a string to a file.
///
/// Opens the file, writes the string in the given encoding, and closes the file.
/// Returns a Future<File> that completes with this File object once the entire
/// operation has completed.
///
/// By default writeAsString creates the file for writing and truncates the file
/// if it already exists. In order to append the bytes to an existing file, pass
/// FileMode.append as the optional mode parameter.
///
/// If the argument flush is set to true, the data written will be flushed to the
/// file system before the returned future completes.
/// @description Checks that in a FileMode.write writeAsString creates the
/// file for writing and truncates the file if it already exists
/// @author sgrekhov@unipro.ru

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

main() async {
  await inSandbox(_main);
}

_main(Directory sandbox) async {
  File file = getTempFileSync(parent: sandbox);
  file.writeAsStringSync("Old content");
  asyncStart();
  String toWrite = "New content";
  await file.writeAsString(toWrite, mode: FileMode.write).then((f) {
    Expect.equals("New content", file.readAsStringSync());
    asyncEnd();
  });
}