Use the new test runner.

test/shelf_proxy_test.dart

Index: test/shelf_proxy_test.dart
diff --git a/test/shelf_proxy_test.dart b/test/shelf_proxy_test.dart
index cf70cb63dc30165f5360052bf5b577efb853f530..b88f059d2397aa74ba33a2ef3d2a1bf4df3f6841 100644
--- a/test/shelf_proxy_test.dart
+++ b/test/shelf_proxy_test.dart
@@ -215,13 +215,13 @@ void main() {
 /// [targetPath] is the root-relative path on the target server to proxy to. It
 /// defaults to `/`.
 void createProxy(shelf.Handler handler, {String targetPath}) {
-  handler = wrapAsync(handler, 'target server handler');
+  handler = expectAsync(handler, reason: 'target server handler');
   schedule(() {
     return shelf_io.serve(handler, 'localhost', 0).then((targetServer) {
       targetUri = Uri.parse('http://localhost:${targetServer.port}');
       if (targetPath != null) targetUri = targetUri.resolve(targetPath);
-      var proxyServerHandler = wrapAsync(
-          proxyHandler(targetUri), 'proxy server handler');
+      var proxyServerHandler = expectAsync(
+          proxyHandler(targetUri), reason: 'proxy server handler');
 
       return shelf_io.serve(proxyServerHandler, 'localhost', 0)
           .then((proxyServer) {