Support Dart 1.8.0.

bin/unittest.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 unittest.unittest;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:isolate';
 
 import 'package:args/args.dart';
 import 'package:stack_trace/stack_trace.dart';
 
 import 'package:unittest/src/console_reporter.dart';
 import 'package:unittest/src/exit_codes.dart' as exit_codes;
+import 'package:unittest/src/io.dart';
 import 'package:unittest/src/load_exception.dart';
 import 'package:unittest/src/loader.dart';
 import 'package:unittest/src/utils.dart';
 
 /// The argument parser used to parse the executable arguments.
 final _parser = new ArgParser();
 
 void main(List<String> args) {
   _parser.addFlag("help", abbr: "h", negatable: false,
       help: "Shows this usage information.");
@@ skipping 52 matching lines @@
           : exit_codes.data;
     } else {
       stderr.writeln(getErrorMessage(error));
       stderr.writeln(new Trace.from(stackTrace).terse);
       stderr.writeln(
           "This is an unexpected error. Please file an issue at "
               "http://github.com/dart-lang/unittest\n"
           "with the stack trace and instructions for reproducing the error.");
       exitCode = exit_codes.software;
     }
-  }).whenComplete(() => loader.close());
+  }).whenComplete(() {
+    return loader.close().then((_) {
+      // If we're on a Dart version that doesn't support Isolate.kill(), we have
+      // to manually exit so that dangling isolates don't prevent it.
+      if (!supportsIsolateKill) exit(exitCode);
+    });
+  });
 }
 
 /// Print usage information for this command.
 ///
 /// If [error] is passed, it's used in place of the usage message and the whole
 /// thing is printed to stderr instead of stdout.
 void _printUsage([String error]) {
   var output = stdout;
 
   var message = "Runs tests in this package.";
   if (error != null) {
     message = error;
     output = stderr;
   }
 
   output.write("""$message
 
 Usage: pub run unittest:unittest [files or directories...]
 
 ${_parser.usage}
 """);
 }