Add expectAsyncX and expectAsyncUntilX methods, and deprecate the old methods.

test/util/path_handler_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.
 
 import 'dart:async';
 
 import 'package:shelf/shelf.dart' as shelf;
 import 'package:test/src/util/path_handler.dart';
 import 'package:test/test.dart';
 
 void main() {
   var handler;
   setUp(() => handler = new PathHandler());
 
   _handle(request) => new Future.sync(() => handler.handler(request));
 
   test("returns a 404 for a root URL", () async {
     var request = new shelf.Request("GET", Uri.parse("http://localhost/"));
     expect((await _handle(request)).statusCode, equals(404));
   });
 
   test("returns a 404 for an unregistered URL", () async {
     var request = new shelf.Request("GET", Uri.parse("http://localhost/foo"));
     expect((await _handle(request)).statusCode, equals(404));
   });
 
   test("runs a handler for an exact URL", () async {
     var request = new shelf.Request("GET", Uri.parse("http://localhost/foo"));
-    handler.add("foo", expectAsync((request) {
+    handler.add("foo", expectAsync1((request) {
       expect(request.handlerPath, equals('/foo'));
       expect(request.url.path, isEmpty);
       return new shelf.Response.ok("good job!");
     }));
 
     var response = await _handle(request);
     expect(response.statusCode, equals(200));
     expect(response.readAsString(), completion(equals("good job!")));
   });
 
   test("runs a handler for a suffix", () async {
     var request = new shelf.Request(
         "GET", Uri.parse("http://localhost/foo/bar"));
-    handler.add("foo", expectAsync((request) {
+    handler.add("foo", expectAsync1((request) {
       expect(request.handlerPath, equals('/foo/'));
       expect(request.url.path, 'bar');
       return new shelf.Response.ok("good job!");
     }));
 
     var response = await _handle(request);
     expect(response.statusCode, equals(200));
     expect(response.readAsString(), completion(equals("good job!")));
   });
 
   test("runs the longest matching handler", () async {
     var request = new shelf.Request(
         "GET", Uri.parse("http://localhost/foo/bar/baz"));
 
-    handler.add("foo", expectAsync((_) {}, count: 0));
-    handler.add("foo/bar", expectAsync((request) {
+    handler.add("foo", expectAsync1((_) {}, count: 0));
+    handler.add("foo/bar", expectAsync1((request) {
       expect(request.handlerPath, equals('/foo/bar/'));
       expect(request.url.path, 'baz');
       return new shelf.Response.ok("good job!");
     }));
-    handler.add("foo/bar/baz/bang", expectAsync((_) {}, count: 0));
+    handler.add("foo/bar/baz/bang", expectAsync1((_) {}, count: 0));
 
     var response = await _handle(request);
     expect(response.statusCode, equals(200));
     expect(response.readAsString(), completion(equals("good job!")));
   });
 }