Make test.dart override only those dependencies declared in the pubspec.yaml

tools/testing/dart/test_runner.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Classes and methods for executing tests.
  *
  * This module includes:
  * - Managing parallel execution of tests, including timeout checks.
  * - Evaluating the output of each test as pass/fail/crash/timeout.
  */
 library test_runner;
 
 import "dart:async";
 import "dart:collection" show Queue;
 import "dart:convert" show LineSplitter, UTF8, JSON;
 // We need to use the 'io' prefix here, otherwise io.exitCode will shadow
 // CommandOutput.exitCode in subclasses of CommandOutput.
 import "dart:io" as io;
 import "dart:math" as math;
+
+import 'package:yaml/yaml.dart';
+
 import 'android.dart';
 import 'dependency_graph.dart' as dgraph;
 import "browser_controller.dart";
 import "path.dart";
 import "status_file_parser.dart";
 import "test_progress.dart";
 import "test_suite.dart";
 import "utils.dart";
 import 'record_and_replay.dart';
 
@@ skipping 432 matching lines @@
   String _destinationFile;
   Map<String, Map> _dependencyOverrides;
 
   ModifyPubspecYamlCommand._(
       this._pubspecYamlFile, this._destinationFile, this._dependencyOverrides)
       : super._("modify_pubspec") {
     assert(_pubspecYamlFile.endsWith("pubspec.yaml"));
     assert(_destinationFile.endsWith("pubspec.yaml"));
   }
 
+  static Map<String, Map> _filterOverrides(
+      String pubspec, Map<String, Map> overrides) {
+    if (overrides.isEmpty) return overrides;
+    var yaml = loadYaml(pubspec);
+    var deps = yaml['dependencies'];
+    var filteredOverrides = <String, Map>{};
+    if (deps != null) {
+      for (var d in deps.keys) {
+        if (!overrides.containsKey(d)) {
+          // pub depends on compiler_unsupported instead of compiler
+          // The dependency is so hackish that we currently ignore it here.
+          if (d == 'compiler_unsupported') continue;
+          throw "Repo doesn't have package $d used in $pubspec";
+        }
+        filteredOverrides[d] = overrides[d];
+      }
+    }
+    return filteredOverrides;
+  }
+
   String get reproductionCommand =>
       "Adding necessary dependency overrides to '$_pubspecYamlFile' "
       "(destination = $_destinationFile).";
 
   Future<ScriptCommandOutputImpl> run() {
     var watch = new Stopwatch()..start();
 
     var pubspecLockFile = _destinationFile.substring(
             0, _destinationFile.length - ".yaml".length) +
         ".lock";
 
     var file = new io.File(_pubspecYamlFile);
     var destinationFile = new io.File(_destinationFile);
     var lockfile = new io.File(pubspecLockFile);
     return file.readAsString().then((String yamlString) {
+      var overrides = _filterOverrides(yamlString, _dependencyOverrides);
       var dependencyOverrideSection = new StringBuffer();
       if (_dependencyOverrides.isNotEmpty) {
         dependencyOverrideSection.write("\n"
             "# This section was autogenerated by test.py!\n"
             "dependency_overrides:\n");
-        _dependencyOverrides.forEach((String packageName, Map override) {
+        overrides.forEach((String packageName, Map override) {
           dependencyOverrideSection.write("  $packageName:\n");
           override.forEach((overrideKey, overrideValue) {
             dependencyOverrideSection
                 .write("    $overrideKey: $overrideValue\n");
           });
         });
       }
       var modifiedYamlString = "$yamlString\n$dependencyOverrideSection";
       return destinationFile.writeAsString(modifiedYamlString).then((_) {
         lockfile.exists().then((bool lockfileExists) {
@@ skipping 2523 matching lines @@
     }
   }
 
   void eventAllTestsDone() {
     for (var listener in _eventListener) {
       listener.allDone();
     }
     _allDone();
   }
 }