Run test tearDowns and clean up temporary directories when a signal is caught.

test/runner/browser/loader_test.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.
 
 @TestOn("vm")
 
 import 'dart:io';
 
 import 'package:path/path.dart' as p;
 import 'package:test/src/backend/state.dart';
 import 'package:test/src/backend/test_platform.dart';
 import 'package:test/src/runner/loader.dart';
+import 'package:test/src/util/io.dart';
 import 'package:test/test.dart';
 
 import '../../io.dart';
 import '../../utils.dart';
 
 Loader _loader;
 String _sandbox;
 
 final _tests = """
 import 'dart:async';
 
 import 'package:test/test.dart';
 
 void main() {
   test("success", () {});
   test("failure", () => throw new TestFailure('oh no'));
   test("error", () => throw 'oh no');
 }
 """;
 
 void main() {
   setUp(() {
     _loader = new Loader([TestPlatform.chrome],
         packageRoot: p.join(packageDir, 'packages'));
-    _sandbox = Directory.systemTemp.createTempSync('test_').path;
+    _sandbox = createTempDir();
     /// TODO(nweiz): Use scheduled_test for this once it's compatible with this
     /// version of test.
     new File(p.join(_sandbox, 'a_test.dart')).writeAsStringSync(_tests);
   });
 
   tearDown(() {
     new Directory(_sandbox).deleteSync(recursive: true);
     return _loader.close();
   });
 
@@ skipping 58 matching lines @@
 
       for (var suite in suites) {
         expect(suite.tests, hasLength(3));
         expect(suite.tests[0].name, equals("success"));
         expect(suite.tests[1].name, equals("failure"));
         expect(suite.tests[2].name, equals("error"));
       }
     }).whenComplete(loader.close);
   });
 }