Make pub generate .packages file.

test/descriptor.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;
 
 import 'package:oauth2/oauth2.dart' as oauth2;
 import 'package:pub/src/io.dart';
 import 'package:pub/src/utils.dart';
 import 'package:scheduled_test/descriptor.dart';
 import 'package:scheduled_test/scheduled_server.dart';
+import 'package:package_config/packages_file.dart' as pkgfile;
 
 import 'descriptor/git.dart';
 import 'descriptor/tar.dart';
 import 'test_pub.dart';
 
 export 'package:scheduled_test/descriptor.dart';
 export 'descriptor/git.dart';
 export 'descriptor/tar.dart';
 
 /// Creates a new [GitRepoDescriptor] with [name] and [contents].
@@ skipping 152 matching lines @@
           ['https://www.googleapis.com/auth/userinfo.email'],
           expiration).toJson())
     ]);
   }));
 }
 
 /// Describes the application directory, containing only a pubspec specifying
 /// the given [dependencies].
 DirectoryDescriptor appDir([Map dependencies]) =>
   dir(appPath, [appPubspec(dependencies)]);
+
+/// Desribe a .packages file.
+///
+/// The file path is relative to [appPath].
+Descriptor dotPackagesFile(String filePath,

[nweiz, 2015/06/10 22:33:59]

I'd just call this "packagesFile".

Having the user explicitly pass in the full path of the descriptor breaks its
ability to be used in arbitrary contexts.

This should return a full descriptor rather than one that can just be used for
validation. It's fine if the descriptor just does textual verification, but it's
important that it can also be used to *create* .packages files. This will become
more important as we move away from packages directories and move more of our
tests over to using packages files instead.

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

Since we changed the file to have only absolute URIs, the location is no longer
needed, so YEY!
ACK.

+                           [Map<String, String> dependencies]) {
+  // Check only for existence.
+  if (dependencies == null) return matcherFile('.packages', (_) => true);
+  // Check contents as well.
+  matchFile(content) {
+    // TODO(lrn): Create a Matcher that gives better error messages.
+    Uri fileLocation = new Uri.directory(appPath).resolve(filePath);

[Lasse Reichstein Nielsen, 2015/06/11 11:21:02]

and p.toUri I guess.

+    var map = pkgfile.parse(content, fileLocation);
+
+    for (var packageName in dependencies.keys) {
+      if (!map.containsKey(packageName)) {
+        return false;
+      }
+      var version = dependencies[packageName];
+      if (!map[packageName].contains(version)) return false;
+    }
+    if (map.length != dependencies.length) return false;
+  }
+  return matcherFile('.packages', matchFile);
+}