dart:io | Add Link class, as sibling to File and Directory.

tests/standalone/io/file_system_links_test.dart

 // Copyright (c) 2012, 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:io";
 import "dart:isolate";
 
 
 createLink(String dst, String link, bool symbolic, void callback()) {

[nweiz, 2013/03/08 20:26:41]

The "symbolic" parameter no longer means anything.

[Bill Hesse, 2013/03/11 09:25:59]

Removed.  This removes a test for hard linking, but it will be restored when
hard links are provided by the Link class.

-  var args = [ symbolic ? '-s' : '', dst, link ];
-  var script = 'tests/standalone/io/ln.sh';
-  if (!new File(script).existsSync()) {
-    script = '../$script';
-  }
-  Process.run(script, args).then((result) {
-    if (result.exitCode == 0) {
-      callback();
-    } else {
-      throw new Exception('link creation failed');
-    }
-  });
+  new Link(link).create(dst, linkRelative: true).then((_) => callback());
 }
 
 
 testFileExistsCreate() {
   var temp = new Directory('').createTempSync();
   var x = '${temp.path}${Platform.pathSeparator}x';
   var y = '${temp.path}${Platform.pathSeparator}y';
   createLink(x, y, true, () {
     Expect.isFalse(new File(y).existsSync());

[nweiz, 2013/03/08 20:26:41]

It's a little weird to me that all these File APIs follow links by default.
Please document this behavior in File.

[Bill Hesse, 2013/03/11 09:25:59]

Done.

     Expect.isFalse(new File(x).existsSync());
     Expect.isTrue(FileSystemEntity.isLinkSync(y));
     Expect.isFalse(FileSystemEntity.isLinkSync(x));
     Expect.equals(FileSystemEntityType.NOT_FOUND, FileSystemEntity.typeSync(y));
     Expect.equals(FileSystemEntityType.NOT_FOUND, FileSystemEntity.typeSync(x));
     Expect.equals(FileSystemEntityType.LINK,
                   FileSystemEntity.typeSync(y, followLinks: false));
     Expect.equals(FileSystemEntityType.NOT_FOUND,
                   FileSystemEntity.typeSync(x, followLinks: false));
 
@@ skipping 118 matching lines @@
 testDirectoryListing() {
   var keepAlive = new ReceivePort();
   var temp = new Directory('').createTempSync();
   var temp2 = new Directory('').createTempSync();
   var y = '${temp.path}${Platform.pathSeparator}y';
   var x = '${temp2.path}${Platform.pathSeparator}x';
   new File(x).createSync();
   createLink(temp2.path, y, true, () {
     var files = [];
     var dirs = [];
     for (var entry in temp.listSync(recursive:true)) {

[nweiz, 2013/03/08 20:26:41]

Shouldn't list start returning Links now?

[Bill Hesse, 2013/03/11 09:25:59]

This will occur in a later change.  It should be made optional, so users can
either see (unfollowed) Links, or their targets, depending on an optional
parameter.

       if (entry is File) {
         files.add(entry.path);
       } else {
         Expect.isTrue(entry is Directory);
         dirs.add(entry.path);
       }
     }
     Expect.equals(1, files.length);
     Expect.isTrue(files[0].endsWith('$y${Platform.pathSeparator}x'));
     Expect.equals(1, dirs.length);
@@ skipping 60 matching lines @@
 
 
 main() {
   testFileExistsCreate();
   testFileDelete();
   testFileWriteRead();
   testDirectoryExistsCreate();
   testDirectoryDelete();
   testDirectoryListing();
   testDirectoryListingBrokenLink();
 }

[nweiz, 2013/03/08 20:26:41]

I assume you're planning on adding a bunch more tests to fully exercise the Link
API?