Add an Environment class that's exposed through RunnerSuite.

lib/src/runner/loader.dart

 // Copyright (c) 2015, 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 test.runner.loader;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:isolate';
 
 import 'package:analyzer/analyzer.dart';
 import 'package:async/async.dart';
 import 'package:path/path.dart' as p;
 import 'package:stack_trace/stack_trace.dart';
 
 import '../backend/invoker.dart';
 import '../backend/metadata.dart';
 import '../backend/test_platform.dart';
 import '../util/dart.dart' as dart;
 import '../util/io.dart';
 import '../util/remote_exception.dart';
 import '../utils.dart';
 import 'browser/server.dart';
 import 'load_exception.dart';
 import 'load_suite.dart';
 import 'parse_metadata.dart';
 import 'runner_suite.dart';
+import 'vm/environment.dart';
 import 'vm/isolate_test.dart';
 
 /// A class for finding test files and loading them into a runnable form.
 class Loader {
   /// All platforms for which tests should be loaded.
   final List<TestPlatform> _platforms;
 
   /// Whether to enable colors for Dart compilation.
   final bool _color;
 
@@ skipping 114 matching lines @@
       return;
     }
 
     for (var platform in _platforms) {
       if (!suiteMetadata.testOn.evaluate(platform, os: currentOS)) continue;
 
       var metadata = suiteMetadata.forPlatform(platform, os: currentOS);
 
       // Don't load a skipped suite.
       if (metadata.skip) {
-        yield new LoadSuite.forSuite(new RunnerSuite([
+        yield new LoadSuite.forSuite(new RunnerSuite(const VMEnvironment(), [
           new LocalTest(path, metadata, () {})
         ], path: path, platform: platform, metadata: metadata));
         continue;
       }
 
       var name = (platform.isJS ? "compiling " : "loading ") + path;
       yield new LoadSuite(name, () {
         return platform == TestPlatform.vm
             ? _loadVmFile(path, metadata)
             : _loadBrowserFile(path, platform, metadata);
@@ skipping 82 matching lines @@
         completer.completeError(
             new LoadException(path, asyncError.error),
             asyncError.stackTrace);
       } else {
         assert(response["type"] == "success");
         completer.complete(response["tests"]);
       }
     });
 
     try {
-      var suite = new RunnerSuite((await completer.future).map((test) {
+      var suite = new RunnerSuite(const VMEnvironment(),

[kevmoo, 2015/07/30 01:37:24]

nested awaits worry me – could make debugging that much more difficult. Pop out
if you think it's okay.

[nweiz, 2015/07/30 19:41:50]

Part of the point of await is that it can be used in subexpressions. I don't
think that makes it any harder to debug than any other subexpression.

+          (await completer.future).map((test) {
         var testMetadata = new Metadata.deserialize(test['metadata']);
         return new IsolateTest(test['name'], testMetadata, test['sendPort']);
       }),
           metadata: metadata,
           path: path,
           platform: TestPlatform.vm,
           os: currentOS,
           onClose: isolate.kill);
       _suites.add(suite);
       return suite;
     } finally {
       subscription.cancel();
     }
   }
 
   /// Closes the loader and releases all resources allocated by it.
   Future close() {
     return _closeMemo.runOnce(() async {
       await Future.wait(_suites.map((suite) => suite.close()));
       _suites.clear();
 
       if (!_browserServerMemo.hasRun) return;
       await (await _browserServer).close();
     });
   }
 }