Fix tests to run in dart-lang/sdk.

lib/src/io.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.
 
 /// Helper functionality to make working with IO easier.
 library pub.io;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
@@ skipping 497 matching lines @@
     r"/third_party/pkg/pub/("
             r"bin/pub\.dart"
         r"|"
             r"\.pub/pub\.test\.snapshot"
         r"|"
             r"test/.*_test\.dart"
         r")$");
 
 /// Whether pub is running from source in the Dart repo.
 ///
-/// This can happen when building Observatory, for example.
-final bool runningFromDartRepo =
-    Platform.script.path.contains(_dartRepoRegExp);
+/// This can happen when running tests against the repo, as well as when
+/// building Observatory.
+final bool runningFromDartRepo = (() {
+  if (runningAsTestRunner) {
+    // When running from the test runner, we can't find our location via
+    // Platform.script since the runner munges that. However, it guarantees that
+    // the working directory is

[Bob Nystrom, 2015/06/30 18:33:11]

"is ..."

[nweiz, 2015/06/30 19:47:29]

Done.

+    return path.current.contains(
+        new RegExp(r"[/\\]third_party[/\\]pkg[/\\]pub$"));
+  } else {
+    return Platform.script.path.contains(_dartRepoRegExp);
+  }
+})();
 
 /// Resolves [target] relative to the path to pub's `asset` directory.
 String assetPath(String target) => runningFromSdk
     ? sdkAssetPath(target)
     : path.join(pubRoot, 'lib', 'src', 'asset', target);
 
 /// Resolves [target] relative to the Dart SDK's `asset` directory.
 ///
 /// Throws a [StateError] if called from within the Dart repo.
 String sdkAssetPath(String target) {
@@ skipping 31 matching lines @@
 
 /// The path to the root of the Dart repo.
 ///
 /// This throws a [StateError] if it's called when not running pub from source
 /// in the Dart repo.
 final String dartRepoRoot = (() {
   if (!runningFromDartRepo) {
     throw new StateError("Not running from source in the Dart repo.");
   }
 
+  if (runningAsTestRunner) {
+    // When running in test code started by the test runner, the working
+    // directory will always be <repo>/third_party/pkg/pub.
+    return path.dirname(path.dirname(path.dirname(path.current)));

[Bob Nystrom, 2015/06/30 18:33:11]

Is there a reason to prefer chained dirnames over path.join(path.current,
"../../../");?

[nweiz, 2015/06/30 19:47:29]

Because path.join tries to avoid any unnecessary modification of the inputs, it
will return "${path.current}/../../..", which is uglier than actually moving up
the directories. Since this path might end up somewhere user-visible, it seems
better to keep it nice-looking.

+  }
+
   // Get the URL of the repo root in a way that works when either both running
   // as a test or as a pub executable.
   var url = Platform.script.replace(
       path: Platform.script.path.replaceAll(_dartRepoRegExp, ''));
   return path.fromUri(url);
 })();
 
 /// A line-by-line stream of standard input.
 final Stream<String> stdinLines = streamToLines(
     new ByteStream(stdin).toStringStream());
@@ skipping 495 matching lines @@
 
   // TODO(rnystrom): Remove this and change to returning one string.
   static List<String> _toLines(String output) {
     var lines = splitLines(output);
     if (!lines.isEmpty && lines.last == "") lines.removeLast();
     return lines;
   }
 
   bool get success => exitCode == exit_codes.SUCCESS;
 }