Adding package:code_transformers for unifying common transformers code

pkg/code_transformers/lib/src/test_harness.dart

Index: pkg/code_transformers/lib/src/test_harness.dart
diff --git a/pkg/polymer/test/build/common.dart b/pkg/code_transformers/lib/src/test_harness.dart
similarity index 76%
copy from pkg/polymer/test/build/common.dart
copy to pkg/code_transformers/lib/src/test_harness.dart
index d7ca4151c727ce97e63c681a3711031e580d90b5..db5390902d1b53cc4978da332e1d5a2198d23719 100644
--- a/pkg/polymer/test/build/common.dart
+++ b/pkg/code_transformers/lib/src/test_harness.dart
@@ -1,8 +1,9 @@
-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2014, 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.
 
-library polymer.test.build.common;
+/// Utilities for creating unit tests of Barback transformers.
+library code_transformers.src.test_harness;
 
 import 'dart:async';
 
@@ -20,15 +21,12 @@ String _removeTrailingWhitespace(String str) =>
     str.splitMapJoin('\n',
         onNonMatch: (s) => s.replaceAll(new RegExp(r'\s+$'), ''));
 
-/**
- * A helper package provider that has files stored in memory, also wraps
- * [Barback] to simply our tests.
- */
+/// A helper package provider that has files stored in memory, also wraps
+/// [Barback] to simply our tests.
 class TestHelper implements PackageProvider {
-  /**
-   * Maps from an asset string identifier of the form 'package|path' to the
-   * file contents.
-   */
+
+  /// Maps from an asset string identifier of the form 'package|path' to the
+  /// file contents.
   final Map<String, String> files;
   final Iterable<String> packages;
   final List<String> messages;
@@ -88,10 +86,8 @@ class TestHelper implements PackageProvider {
     logSubscription.cancel();
   }
 
-  /**
-   * Tells barback which files have changed, and thus anything that depends on
-   * it on should be computed. By default mark all the input files.
-   */
+  /// Tells barback which files have changed, and thus anything that depends on
+  /// it on should be computed. By default mark all the input files.
   void run([Iterable<String> paths]) {
     if (paths == null) paths = files.keys;
     barback.updateSources(paths.map(idFromString));
@@ -126,20 +122,3 @@ class TestHelper implements PackageProvider {
     });
   }
 }
-
-testPhases(String testName, List<List<Transformer>> phases,
-    Map<String, String> inputFiles, Map<String, String> expectedFiles,
-    [List<String> expectedMessages]) {
-  test(testName, () {
-    var helper = new TestHelper(phases, inputFiles, expectedMessages)..run();
-    return helper.checkAll(expectedFiles).then((_) => helper.tearDown());
-  });
-}
-
-const WEB_COMPONENTS_TAG =
-    '<script src="packages/web_components/platform.js"></script>\n'
-    '<script src="packages/web_components/dart_support.js"></script>\n';
-
-const INTEROP_TAG = '<script src="packages/browser/interop.js"></script>\n';
-const DART_JS_TAG = '<script src="packages/browser/dart.js"></script>';
-