Modify tests to use Directory.systemTemp

tests/standalone/io/link_async_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.
 
 import "dart:async";
 import "dart:io";
 
 import "package:async_helper/async_helper.dart";
 import "package:expect/expect.dart";
 import "package:path/path.dart";
@@ skipping 11 matching lines @@
       result.then((value) => Expect.listEquals(expected, value));
   static Future throws(Future result) =>
       result.then((value) {
         throw new ExpectException(
             "FutureExpect.throws received $value instead of an exception");
         }, onError: (_) => null);
 }
 
 
 Future testCreate() {
-  return new Directory('').createTemp().then((baseDir) {
+  return Directory.systemTemp.createTemp('dart_link_async').then((baseDir) {
+    if (isRelative(baseDir.path)) {
+      Expect.fail(
+          'Link tests expect absolute paths to system temporary directories. '
+          'A relative path in TMPDIR gives relative paths to them.');
+    }
     String base = baseDir.path;
     String link = join(base, 'link');
     String target = join(base, 'target');
     return new Directory(target).create()
     .then((_) => new Link(link).create(target))
 
     .then((_) => FutureExpect.equals(FileSystemEntityType.DIRECTORY,
                                      FileSystemEntity.type(link)))
     .then((_) => FutureExpect.equals(FileSystemEntityType.DIRECTORY,
                                      FileSystemEntity.type(target)))
@@ skipping 91 matching lines @@
         }
         return Future.wait(futures);
       })
       .then((_) => baseDir.delete(recursive: true));
     });
   });
 }
 
 
 Future testCreateLoopingLink(_) {
-  return new Directory('').createTemp()
+  return Directory.systemTemp.createTemp('dart_link_async')
     .then((dir) => dir.path)
     .then((String base) =>
       new Directory(join(base, 'a', 'b', 'c')).create(recursive: true)
         .then((_) => new Link(join(base, 'a', 'b', 'c', 'd'))
             .create(join(base, 'a', 'b')))
         .then((_) => new Link(join(base, 'a', 'b', 'c', 'e'))
             .create(join(base, 'a')))
         .then((_) => new Directory(join(base, 'a'))
             .list(recursive: true, followLinks: false).last)
         // This directory listing must terminate, even though it contains loops.
@@ skipping 38 matching lines @@
     .then((Link link) {
       Expect.isTrue(link1.existsSync());
       Expect.isTrue(link.existsSync());
       return FutureExpect.equals(target2, link.target())
       .then((_) => FutureExpect.equals(target2, link1.target()))
       .then((_) => link.delete());
     })
     .then((_) => Expect.isFalse(link1.existsSync()));
   }
 
-  return new Directory('').createTemp().then((baseDir) {
+  return Directory.systemTemp.createTemp('dart_link_async').then((baseDir) {
     String base = baseDir.path;
     var targetsFutures = [];
     targetsFutures.add(new Directory(join(base, 'a')).create());
     if (Platform.isWindows) {
       // Currently only links to directories are supported on Windows.
       targetsFutures.add(
           new Directory(join(base, 'b')).create());
     } else {
       targetsFutures.add(new File(join(base, 'b')).create());
     }
@@ skipping 54 matching lines @@
       );
     }
   }
   return Future.wait(futures);
 }
 
 Future checkExists(String filePath) =>
     new File(filePath).exists().then(Expect.isTrue);
 
 Future testRelativeLinks(_) {
-  return new Directory('').createTemp().then((tempDirectory) {
+  return Directory.systemTemp
+                  .createTemp('dart_link_async')
+                  .then((tempDirectory) {
     String temp = tempDirectory.path;
     String oldWorkingDirectory = Directory.current.path;
     // Make directories and files to test links.
     return new Directory(join(temp, 'dir1', 'dir2')).create(recursive: true)
     .then((_) => new File(join(temp, 'dir1', 'file1')).create())
     .then((_) => new File(join(temp, 'dir1', 'dir2', 'file2')).create())
     // Make links whose path and/or target is given by a relative path.
     .then((_) => new Link(join(temp, 'dir1', 'link1_2')).create('dir2'))
     .then((_) => Directory.current = temp)
     .then((_) => new Link('link0_2').create(join('dir1', 'dir2')))
@@ skipping 17 matching lines @@
 }
 
 main() {
   asyncStart();
   testCreate()
     .then(testCreateLoopingLink)
     .then(testRename)
     .then(testRelativeLinks)
     .then((_) => asyncEnd());
 }