Make sure handler errors won't bring down a shelf server.

pkg/shelf/test/shelf_io_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 shelf_io_test;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
@@ skipping 166 matching lines @@
         expect(body, 'test body');
         return syncHandler(request);
       });
     });
 
     return _schedulePost(body: 'test body').then((response) {
       expect(response.statusCode, HttpStatus.OK);
       expect(response.stream.bytesToString(), completion('Hello from /'));
     });
   });
+
+  test('passes asynchronous exceptions to the parent error zone', () {
+    return runZoned(() {
+      return shelf_io.serve((request) {
+        new Future(() => throw 'oh no');
+        return syncHandler(request);
+      }, 'localhost', 0).then((server) {
+        return http.get('http://localhost:${server.port}').then((response) {
+          expect(response.statusCode, HttpStatus.OK);
+          expect(response.body, 'Hello from /');
+          server.close();
+        });
+      });
+    }, onError: expectAsync((error) {
+      expect(error, equals('oh no'));
+    }));
+  });
+
+  test("doesn't pass asynchronous exceptions to the root error zone", () {
+    return Zone.ROOT.run(() {
+      return shelf_io.serve((request) {
+        new Future(() => throw 'oh no');
+        return syncHandler(request);
+      }, 'localhost', 0).then((server) {
+        return http.get('http://localhost:${server.port}').then((response) {
+          expect(response.statusCode, HttpStatus.OK);
+          expect(response.body, 'Hello from /');
+          server.close();
+        });
+      });
+    });
+  });
 }
 
 int _serverPort;
 
 Future _scheduleServer(Handler handler) {
   return schedule(() => shelf_io.serve(handler, 'localhost', 0).then((server) {
     currentSchedule.onComplete.schedule(() {
       _serverPort = null;
       return server.close(force: true);
     });
@@ skipping 16 matching lines @@
 
     var request = new http.Request('POST',
         Uri.parse('http://localhost:$_serverPort/'));
 
     if (headers != null) request.headers.addAll(headers);
     if (body != null) request.body = body;
 
     return request.send();
   });
 }