Change the way we look up packages for tests.

test/test_pub.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.
 
 /// Test infrastructure for testing pub.
 ///
 /// Unlike typical unit tests, most pub tests are integration tests that stage
 /// some stuff on the file system, run pub, and then validate the results. This
 /// library provides an API to build tests like that.
 library test_pub;
@@ skipping 61 matching lines @@
 /// A [Matcher] that matches JavaScript generated by dart2js with minification
 /// enabled.
 Matcher isMinifiedDart2JSOutput =
     isNot(contains("// The code supports the following hooks"));
 
 /// A [Matcher] that matches JavaScript generated by dart2js with minification
 /// disabled.
 Matcher isUnminifiedDart2JSOutput =
     contains("// The code supports the following hooks");
 
+/// The entrypoint for pub itself.
+final _entrypoint = new Entrypoint(
+    pubRoot, new SystemCache.withSources(isOffline: true));
+
 /// A map from package names to paths from which those packages should be loaded
 /// for [createLockFile].
 ///
 /// This allows older versions of dependencies than those that exist in the repo
 /// to be used when testing pub.
 Map<String, String> _packageOverrides;
 
-/// A map from barback versions to the paths of directories in the repo
-/// containing them.
+/// A map from barback versions to the paths to directories containing them.
 ///
 /// This includes the latest version of barback from pkg as well as all old
 /// versions of barback in third_party.
 final _barbackVersions = _findBarbackVersions();
 
 /// Some older barback versions require older versions of barback's dependencies
 /// than those that are in the repo.
 ///
 /// This is a map from barback version ranges to the dependencies for those
 /// barback versions. Each dependency version listed here should be included in
 /// third_party/pkg.
 final _barbackDeps = {
   new VersionConstraint.parse("<0.15.0"): {
     "source_maps": "0.9.4"
   }
 };
 
 /// Populates [_barbackVersions].
 Map<Version, String> _findBarbackVersions() {
   var versions = {};
-  var currentBarback = p.join(repoRoot, 'third_party', 'pkg', 'barback');
-  versions[new Pubspec.load(currentBarback, new SourceRegistry()).version] =
-      currentBarback;
 
-  for (var dir in listDir(p.join(repoRoot, 'third_party', 'pkg'))) {
+  // It would be nice if this could use HostedSource's logic, but it's
+  // asynchronous and this is a variable initializer.
+  var currentBarback = packagePath('barback');
+  versions[_entrypoint.lockFile.packages['barback'].version] = currentBarback;
+
+  for (var dir in listDir(p.join(pubRoot, 'third_party'))) {
     var basename = p.basename(dir);
     if (!basename.startsWith('barback-')) continue;
     versions[new Version.parse(split1(basename, '-').last)] = dir;
   }
 
   return versions;
 }
 
 /// Runs the tests in [callback] against all versions of barback in the repo
 /// that match [versionConstraint].
@@ skipping 10 matching lines @@
         'No available barback version matches "$versionConstraint".');
   }
 
   for (var version in validVersions) {
     group("with barback $version", () {
       setUp(() {
         _packageOverrides = {};
         _packageOverrides['barback'] = _barbackVersions[version];
         _barbackDeps.forEach((constraint, deps) {
           if (!constraint.allows(version)) return;
+
           deps.forEach((packageName, version) {
             _packageOverrides[packageName] = p.join(
-                repoRoot, 'third_party', 'pkg', '$packageName-$version');
+                pubRoot, 'third_party', '$packageName-$version');
           });
         });
 
         currentSchedule.onComplete.schedule(() {
           _packageOverrides = null;
         });
       });
 
       callback();
     });
@@ skipping 651 matching lines @@
   if (hosted != null) {
     hosted.forEach((name, version) {
       var id = new PackageId(name, 'hosted', new Version.parse(version), name);
       lockFile.packages[name] = id;
     });
   }
 
   return lockFile;
 }
 
-/// Returns the path to [package] within the repo.
-String packagePath(String package) =>
-    dirExists(p.join(repoRoot, 'pkg', package)) ?
-        p.join(repoRoot, 'pkg', package) :
-        p.join(repoRoot, 'third_party', 'pkg', package);
+/// Returns the path to the version of [package] used by pub.
+String packagePath(String package) {
+  var id = _entrypoint.lockFile.packages[package];
+  if (id == null) {
+    throw new StateError(
+        'The tests rely on "$package", but it\'s not in the lockfile.');
+  }
+
+  return p.join(
+      SystemCache.defaultDir,
+      'hosted/pub.dartlang.org/$package-${id.version}');
+}
 
 /// Uses [client] as the mock HTTP client for this test.
 ///
 /// Note that this will only affect HTTP requests made via http.dart in the
 /// parent process.
 void useMockClient(MockClient client) {
   var oldInnerClient = innerHttpClient;
   innerHttpClient = client;
   currentSchedule.onComplete.schedule(() {
     innerHttpClient = oldInnerClient;
@@ skipping 179 matching lines @@
         _lastMatcher.matches(item.last, matchState);
   }
 
   Description describe(Description description) {
     return description.addAll("(", ", ", ")", [_firstMatcher, _lastMatcher]);
   }
 }
 
 /// A [StreamMatcher] that matches multiple lines of output.
 StreamMatcher emitsLines(String output) => inOrder(output.split("\n"));