| // 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.append string is appended to an |
| /// existing file |
| /// @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.append).then((f) { |
| Expect.equals("Old content New content", file.readAsStringSync()); |
| asyncEnd(); |
| }); |
| } |