Update dart:io tests to use asyncStart/asyncEnd

tests/standalone/io/file_input_stream_test.dart

 // Copyright (c) 2013, 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.
 // Testing file input stream, VM-only, standalone test.
 
 import "dart:convert";
 import "dart:io";
-import "dart:isolate";
 
+import "package:async_helper/async_helper.dart";
 import "package:expect/expect.dart";
 
 // Helper method to be able to run the test from the runtime
 // directory, or the top directory.
 String getFilename(String path) =>
     new File(path).existsSync() ? path : '../$path';
 
 void testStringLineSplitter() {
   String fileName = getFilename("tests/standalone/io/readuntil_test.dat");
   // File contains "Hello Dart\nwassup!\n"
   File file = new File(fileName);
   int linesRead = 0;
   var lineStream = file.openRead()
     .transform(UTF8.decoder)
     .transform(new LineSplitter());
   lineStream.listen((line) {
     linesRead++;
     if (linesRead == 1) {
       Expect.equals("Hello Dart", line);
     } else if (linesRead == 2) {
       Expect.equals("wassup!", line);
     } else {
       Expect.fail("More or less than 2 lines read ($linesRead lines read).");
     }
   });
 }
 
 
 void testOpenStreamAsync() {
-  var keepAlive = new ReceivePort();
+  asyncStart();
   String fileName = getFilename("tests/standalone/io/readuntil_test.dat");
   // File contains "Hello Dart\nwassup!\n"
   var expected = "Hello Dart\nwassup!\n".codeUnits;
   var byteCount = 0;
   (new File(fileName)).openRead().listen(
       (d) => byteCount += d.length,
       onDone: () {
         Expect.equals(expected.length, byteCount);
-        keepAlive.close();
+        asyncEnd();
       });
 }
 
 
 // Create a file that is big enough that a file stream will
 // read it in multiple chunks.
 int writeLongFileSync(File file) {
   file.createSync();
   StringBuffer buffer = new StringBuffer();
   for (var i = 0; i < 10000; i++) {
     buffer.write("Hello, world");
   }
   file.writeAsStringSync(buffer.toString());
   var length = file.lengthSync();
   Expect.equals(buffer.length, length);
   return length;
 }
 
 
 void testInputStreamTruncate() {
-  var keepAlive = new ReceivePort();
+  asyncStart();
   var temp = new Directory('').createTempSync();
   var file = new File('${temp.path}/input_stream_truncate.txt');
   var originalLength = writeLongFileSync(file);
   // Start streaming the file. Pause after first chunk. Truncate
   // underlying file and check that the streaming stops with or
   // without getting all data.
   var streamedBytes = 0;
   var subscription;
   subscription = file.openRead().listen(
       (d) {
         if (streamedBytes == 0) {
           subscription.pause();
           // Truncate the file by opening it for writing.
           file.open(mode: FileMode.WRITE).then((opened) {
             opened.close().then((_) {
                 Expect.equals(0, file.lengthSync());
                 subscription.resume();
             });
           });
         }
         streamedBytes += d.length;
       },
       onDone: () {
         Expect.isTrue(streamedBytes > 0 && streamedBytes <= originalLength);
-        temp.delete(recursive: true).then((_) => keepAlive.close());
+        temp.delete(recursive: true).then((_) => asyncEnd());
       },
       onError: (e) {
         Expect.fail("Unexpected error");
       });
 }
 
 void testInputStreamDelete() {
-  var keepAlive = new ReceivePort();
+  asyncStart();
   var temp = new Directory('').createTempSync();
   var file = new File('${temp.path}/input_stream_delete.txt');
   var originalLength = writeLongFileSync(file);
   // Start streaming the file. Pause after first chunk. Truncate
   // underlying file and check that the streaming stops with or
   // without getting all data.
   var streamedBytes = 0;
   var subscription;
   subscription = file.openRead().listen(
       (d) {
@@ skipping 10 matching lines @@
               // somewhere else. The stream has this file open
               // and therefore we get an error on deletion on Windows.
               Expect.equals('windows', Platform.operatingSystem);
               subscription.resume();
             });
         }
         streamedBytes += d.length;
       },
       onDone: () {
         Expect.equals(originalLength, streamedBytes);
-        temp.delete(recursive: true).then((_) => keepAlive.close());
+        temp.delete(recursive: true).then((_) => asyncEnd());
       },
       onError: (e) {
         Expect.fail("Unexpected error");
       });
 }
 
 
 void testInputStreamAppend() {
-  var keepAlive = new ReceivePort();
+  asyncStart();
   var temp = new Directory('').createTempSync();
   var file = new File('${temp.path}/input_stream_append.txt');
   var originalLength = writeLongFileSync(file);
   // Start streaming the file. Pause after first chunk. Append to
   // underlying file and check that the stream gets all the data.
   var streamedBytes = 0;
   var subscription;
   subscription = file.openRead().listen(
       (d) {
         if (streamedBytes == 0) {
           subscription.pause();
           // Double the length of the underlying file.
           file.readAsBytes().then((bytes) {
             file.writeAsBytes(bytes, mode: FileMode.APPEND).then((_) {
               Expect.equals(2 * originalLength, file.lengthSync());
               subscription.resume();
             });
           });
         }
         streamedBytes += d.length;
       },
       onDone: () {
         Expect.equals(2 * originalLength, streamedBytes);
-        temp.delete(recursive: true).then((_) => keepAlive.close());
+        temp.delete(recursive: true).then((_) => asyncEnd());
       },
       onError: (e) {
         Expect.fail("Unexpected error");
       });
 }
 
 
 void testInputStreamOffset() {
   void test(int start, int end, int expectedBytes) {
-    var keepAlive = new ReceivePort();
+    asyncStart();
     var temp = new Directory('').createTempSync();
     var file = new File('${temp.path}/input_stream_offset.txt');
     var originalLength = writeLongFileSync(file);
     var streamedBytes = 0;
     if (expectedBytes < 0) expectedBytes = originalLength + expectedBytes;
     file.openRead(start, end).listen(
         (d) {
           streamedBytes += d.length;
         },
         onDone: () {
           Expect.equals(expectedBytes, streamedBytes);
-          temp.delete(recursive: true).then((_) => keepAlive.close());
+          temp.delete(recursive: true).then((_) => asyncEnd());
         },
         onError: (e) {
           Expect.fail("Unexpected error");
         });
   }
   test(10, 20, 10);
   test(10, 11, 1);
   test(10, 10, 0);
   test(100000000, null, 0);
   test(null, 0, 0);
   test(null, 1, 1);
   test(1, null, -1);
   test(20, null, -20);
 }
 
 
 void testInputStreamBadOffset() {
   void test(int start, int end) {
-    var keepAlive = new ReceivePort();
+    asyncStart();
     var temp = new Directory('').createTempSync();
     var file = new File('${temp.path}/input_stream_bad_offset.txt');
     var originalLength = writeLongFileSync(file);
     var streamedBytes = 0;
     file.openRead(start, end).listen(
         (d) {
           streamedBytes += d.length;
         },
         onDone: () {
           temp.delete(recursive: true);
         },
         onError: (e) {
-          keepAlive.close();
+          asyncEnd();
         });
   }
   test(-1, null);
   test(100, 99);
   test(null, -1);
 }
 
 
 void testStringLineSplitterEnding(String name, int length) {
   String fileName = getFilename("tests/standalone/io/$name");
@@ skipping 25 matching lines @@
   testInputStreamDelete();
   testInputStreamAppend();
   testInputStreamOffset();
   testInputStreamBadOffset();
   // Check the length of these files as both are text files where one
   // is without a terminating line separator which can easily be added
   // back if accidentally opened in a text editor.
   testStringLineSplitterEnding("readline_test1.dat", 111);
   testStringLineSplitterEnding("readline_test2.dat", 114);
 }