Add web socket command to stop serving a directory.

sdk/lib/_internal/pub/test/serve/utils.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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 pub_tests;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
@@ skipping 221 matching lines @@
 ///
 /// [root] indicates which server should be accessed, and defaults to "web".
 void postShould405(String urlPath, {String root}) {
   schedule(() {
     return http.post(_getServerUrlSync(root, urlPath)).then((response) {
       expect(response.statusCode, equals(405));
     });
   }, "request $urlPath");
 }
 
+/// Schedules an HTTP request to the (theoretically) running pub server with
+/// [urlPath] and verifies that it cannot be connected to.
+///
+/// [root] indicates which server should be accessed, and defaults to "web".
+void requestShouldNotConnect(String urlPath, {String root}) {
+  schedule(() {
+    return expect(http.get(_getServerUrlSync(root, urlPath)),
+        throwsA(new isInstanceOf<SocketException>()));
+  }, "request $urlPath");
+}
+
 /// Reads lines from pub serve's stdout until it prints the build success
 /// message.
 ///
 /// The schedule will not proceed until the output is found. If not found, it
 /// will eventually time out.
 void waitForBuildSuccess() =>
   _pubServer.stdout.expect(consumeThrough(contains("successfully")));
 
 /// Schedules opening a web socket connection to the currently running pub
 /// serve.
@@ skipping 78 matching lines @@
 /// included. Unlike [getServerUrl], this should only be called after the ports
 /// are known.
 String _getServerUrlSync([String root, String path]) {
   if (root == null) root = 'web';
   expect(_ports, contains(root));
   var url = "http://127.0.0.1:${_ports[root]}";
   if (path != null) url = "$url/$path";
   return url;
 }