Split out a RunnerSuite class.

lib/src/backend/suite.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.backend.suite;
 
-import 'dart:async';
 import 'dart:collection';
 
-import '../util/async_thunk.dart';
-import '../utils.dart';
 import 'metadata.dart';
 import 'operating_system.dart';
 import 'test.dart';
 import 'test_platform.dart';
 
 /// A test suite.
 ///
 /// A test suite is a set of tests that are intended to be run together and that
 /// share default configuration.
 class Suite {
   /// The platform on which the suite is running, or `null` if that platform is
   /// unknown.
   final TestPlatform platform;
 
   /// The operating system on which the suite is running, or `null` if that
   /// operating system is unknown.
   ///
   /// This will always be `null` if [platform] is `null`.
   final OperatingSystem os;
 
   /// The path to the Dart test suite, or `null` if that path is unknown.
   final String path;
 
   /// The metadata associated with this test suite.
   final Metadata metadata;
 
-  /// The thunk for running [close] exactly once.
-  final _closeThunk = new AsyncThunk();
-
-  /// The function to call when the suite is closed.
-  final AsyncFunction _onClose;
-
   /// The tests in the test suite.
   final List<Test> tests;
 
   /// Creates a new suite containing [tests].
   ///
   /// If [platform] and/or [os] are passed, [tests] and [metadata] are filtered
   /// to match that platform information.
   ///
   /// If [os] is passed without [platform], throws an [ArgumentError].
   Suite(Iterable<Test> tests, {this.path, TestPlatform platform,
-          OperatingSystem os, Metadata metadata, AsyncFunction onClose})
+          OperatingSystem os, Metadata metadata})
       : platform = platform,
         os = os,
         metadata = _filterMetadata(metadata, platform, os),
-        _onClose = onClose,
         tests = new UnmodifiableListView<Test>(
             _filterTests(tests, platform, os));
 
   /// Returns [metadata] filtered according to [platform] and [os].
   ///
   /// Gracefully handles either [metadata] or [platform] being null.
   static Metadata _filterMetadata(Metadata metadata, TestPlatform platform,
       OperatingSystem os) {
     if (platform == null && os != null) {
       throw new ArgumentError.value(null, "os",
@@ skipping 21 matching lines @@
 
   /// Returns a new suite with the given fields updated.
   ///
   /// In the new suite, [metadata] and [tests] will be filtered according to
   /// [platform] and [os].
   Suite change({String path, Metadata metadata, Iterable<Test> tests}) {
     if (path == null) path = this.path;
     if (metadata == null) metadata = this.metadata;
     if (tests == null) tests = this.tests;
     return new Suite(tests, platform: platform, os: os, path: path,
-        metadata: metadata, onClose: this.close);
-  }
-
-  /// Closes the suite and releases any resources associated with it.
-  Future close() {
-    return _closeThunk.run(() async {
-      if (_onClose != null) await _onClose();
-    });
+        metadata: metadata);
   }
 }