Add an http_multi_server package.

pkg/http_multi_server/test/http_multi_server_test.dart

+// Copyright (c) 2014, 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 http_multi_server.test;
+
+import 'dart:async';
+import 'dart:io';
+
+import 'package:http/http.dart' as http;
+import 'package:http_multi_server/http_multi_server.dart';
+import 'package:http_multi_server/src/utils.dart';
+import 'package:unittest/unittest.dart';
+
+void main() {
+  group("with multiple HttpServers", () {
+    var multiServer;
+    var subServer1;
+    var subServer2;
+    var subServer3;
+    setUp(() {
+      return Future.wait([
+        HttpServer.bind("127.0.0.1", 0).then((server) {
+          subServer1 = server;
+          return server;
+        }),

[Bob Nystrom, 2014/06/04 23:58:17]

You could just do:

.then((server) => subServer1 = server)

[nweiz, 2014/06/05 00:36:09]

Done.

+        HttpServer.bind("127.0.0.1", 0).then((server) {
+          subServer2 = server;
+          return server;
+        }),
+        HttpServer.bind("127.0.0.1", 0).then((server) {
+          subServer3 = server;
+          return server;
+        })
+      ]).then((servers) => multiServer = new HttpMultiServer(servers));
+    });
+
+    tearDown(() => multiServer.close());
+
+    test("listen listens to all servers", () {
+      multiServer.listen((request) {
+        request.response.write("got request");
+        request.response.close();
+      });
+
+      expect(_read(subServer1), completion(equals("got request")));
+      expect(_read(subServer2), completion(equals("got request")));
+      expect(_read(subServer3), completion(equals("got request")));
+    });
+
+    test("serverHeader= sets the value for all servers", () {
+      multiServer.serverHeader = "http_multi_server test";
+
+      multiServer.listen((request) {
+        request.response.write("got request");
+        request.response.close();
+      });
+
+      expect(_get(subServer1).then((response) {
+        expect(response.headers['server'], equals("http_multi_server test"));
+      }), completes);
+
+      expect(_get(subServer2).then((response) {
+        expect(response.headers['server'], equals("http_multi_server test"));
+      }), completes);
+
+      expect(_get(subServer3).then((response) {
+        expect(response.headers['server'], equals("http_multi_server test"));
+      }), completes);
+    });
+
+    test("connectionsInfo sums the values for all servers", () {
+      var pendingRequests = 0;
+      var awaitingResponseCompleter = new Completer();
+      var sendResponseCompleter = new Completer();
+      multiServer.listen((request) {
+        sendResponseCompleter.future.then((_) {
+          request.response.write("got request");
+          request.response.close();
+        });
+
+        pendingRequests++;
+        if (pendingRequests == 2) awaitingResponseCompleter.complete();
+      });
+
+      // Queue up some requests, then wait to make sure they're 

[Bob Nystrom, 2014/06/04 23:58:17]

Don't leave me hanging!

[nweiz, 2014/06/05 00:36:09]

Done.

+      expect(_get(subServer1), completes);
+      expect(_get(subServer2), completes);
+
+      return awaitingResponseCompleter.future.then((_) {
+        var info = multiServer.connectionsInfo();
+        expect(info.total, equals(2));
+        expect(info.active, equals(2));
+        expect(info.idle, equals(0));
+        expect(info.closing, equals(0));
+
+        sendResponseCompleter.complete();
+      });
+    });
+  });
+
+  group("HttpMultiServer.loopback", () {
+    var server;
+    setUp(() {
+      return HttpMultiServer.loopback(0).then((server_) => server = server_);
+    });
+
+    tearDown(() => server.close());
+
+    test("listens on all localhost interfaces", () {
+      server.listen((request) {
+        request.response.write("got request");
+        request.response.close();
+      });
+
+      expect(http.read("http://127.0.0.1:${server.port}/"),
+          completion(equals("got request")));
+
+      return supportsIpV6.then((supportsIpV6) {

[Bob Nystrom, 2014/06/04 23:58:17]

I'm iffy about this check. It's possible for us to have no IPv6 coverage and not
know it if none of the bots happen to support it. (Especially since many of the
issues this package solves have only appeared on the bots.) How about making a
separate IPv6 test and then use status files to control which bots it runs on?

[nweiz, 2014/06/05 00:36:09]

I really don't want to be in the business of maintaining a list of which bots do
and don't support IPv6. In practice I'm sure almost all of them do and will
continue to indefinitely; we've already seen that a number of bots do support it
by seeing the errors that this is working around.

+        if (!supportsIpV6) return;
+        expect(http.read("http://[::1]:${server.port}/"),
+            completion(equals("got request")));
+      });
+    });
+  });
+}
+
+/// Makes a GET request to the root of [server] and returns the response.
+Future<http.Response> _get(HttpServer server) => http.get(_urlFor(server));
+
+/// Makes a GET request to the root of [server] and returns the response body.
+Future<String> _read(HttpServer server) => http.read(_urlFor(server));
+
+/// Returns the URL for the root of [server].
+String _urlFor(HttpServer server) =>
+    "http://${server.address.host}:${server.port}/";