Work in progres, please take a look and give early feedback if this is the way we want to structure…

tests/io/file_test.dart

 // Copyright (c) 2015, the Fletch 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.md file.
 
 import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:expect/expect.dart';
 
 void main() {
   testOpen();
   testReadWrite();
   testSeek();
 }
 
 bool isFileException(e) => e is FileException;
 
 void testOpen() {
   String path = '/tmp/__fletch_dart_io_non_exist_file__';
   Expect.throws(() => new File.open(path), isFileException);
-
   var file = new File.temporary("/tmp/file_test");
   Expect.isTrue(file.isOpen);
   Expect.isTrue(File.existsAsFile(file.path));
   file.close();
   Expect.isFalse(file.isOpen);
   File.delete(file.path);
   Expect.isFalse(File.existsAsFile(file.path));
 }
 
 void testReadWrite() {
@@ skipping 28 matching lines @@
   Expect.equals(0, file.length);
   file.position = 0;
   Expect.equals(0, file.position);
   file.position = 1;
   Expect.equals(1, file.position);
   Expect.equals(0, file.length);
 
   file.close();
   File.delete(file.path);
 }