Fix packages_file_test on OS X.

test/descriptor/packages.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.
 
 /// Pub-specific scheduled_test descriptors.
 library descriptor.packages_file;
 
 import "dart:io" show File;
 import "dart:async" show Future;
 import "dart:convert" show UTF8;
 
 import 'package:package_config/packages_file.dart' as packages_file;
 import 'package:path/path.dart' as p;
 import 'package:scheduled_test/descriptor.dart';
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../test_pub.dart';
 
 /// Describes a `.packages` file and its contents.
 class PackagesFileDescriptor extends Descriptor {
   // RegExp recognizing semantic version numbers.
   static final _semverRE =
       new RegExp(r"^(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)"
                 r"(?:-[a-zA-Z\d-]+)?(?:\+[a-zA-Z\d-]+)?$");
 
-  final _dependencies;
+  /// A map from package names to strings describing where the packages are
+  /// located on disk.
+  final Map<String, String> _dependencies;
 
   /// Describes a `.packages` file with the given dependencies.
   ///
-  /// Dependencies maps package name to semantic version.
-  PackagesFileDescriptor([Map<String, String> dependencies])
-      : _dependencies = dependencies,
-        super('.packages');
+  /// [dependencies] maps package names to strings describing where the packages
+  /// are located on disk.
+  PackagesFileDescriptor([this._dependencies]) : super('.packages');
 
   Future create([String parent]) => schedule(() {
     if (parent == null) parent = defaultRoot;
     var contents = const <int>[];
     if (_dependencies != null) {
       var mapping = {};
       _dependencies.forEach((package, version) {
         var packagePath;
         if (_semverRE.hasMatch(version)) {
           // If it's a semver, it's a cache reference.
           packagePath = p.join(cachePath, "$package-$version");
         } else {
           // Otherwise it's a path relative to the .pubspec file,
           // which is also the relative path wrt. the .packages file.
-          packagePath = version;
+          packagePath = p.fromUri(version);
         }
         mapping[package] = p.toUri(p.join(packagePath, "lib", ""));
       });
       var buffer = new StringBuffer();
       packages_file.write(buffer, mapping);
       contents = UTF8.encode(buffer.toString());
     }
     return new File(p.join(parent, name)).writeAsBytes(contents);
   }, "creating file '$name'");
 
@@ skipping 14 matching lines @@
   /// A function that throws an error if [binaryContents] doesn't match the
   /// expected contents of the descriptor.
   void _validateNow(List<int> binaryContents, String fullPath) {
     var fileUri = p.toUri(fullPath);
     var map = packages_file.parse(binaryContents, fileUri);
 
     for (var package in _dependencies.keys) {
       if (!map.containsKey(package)) {
         fail(".packages does not contain $package entry");
       }
-      var version = _dependencies[package];
-      if (_semverRE.hasMatch(version)) {
-        if (!map[package].path.contains(version)) {
+
+      var description = _dependencies[package];
+      if (_semverRE.hasMatch(description)) {
+        if (!map[package].path.contains(description)) {
           fail(".packages of $package has incorrect version. "
-               "Expected $version, found location: ${map[package]}.");
+               "Expected $description, found location: ${map[package]}.");
         }
       } else {
-        var packagePath = fileUri.resolve("$version/lib/");
-        if (!packagePath.path.endsWith('/')) {
-          packagePath = packagePath.replace(path: packagePath.path + '/');
-        }
-        if ("${map[package]}" != "$packagePath") {
-          fail("Relative path: Expected $packagePath, found ${map[package]}");
+        var expected = p.normalize(p.join(
+            p.dirname(fullPath), p.fromUri(description), 'lib'));
+        expected = new File(expected).resolveSymbolicLinksSync();
+        var actual = new File(p.normalize(p.absolute(p.fromUri(map[package]))))
+            .resolveSymbolicLinksSync();
+
+        if (expected != actual) {
+          fail("Relative path: Expected $description, found ${map[package]}");
         }
       }
     }
 
     if (map.length != _dependencies.length) {
       for (var key in map.keys) {
         if (!_dependencies.containsKey(key)) {
           fail(".packages file contains unexpected entry: $key");
         }
       }
     }
   }
 
   String describe() => name;
 }