pkg/shelf: Fixed logic for setting Server header in `shelf_io`

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 266 matching lines @@
         });
       });
 
       return _scheduleGet().then((response) {
         expect(response.headers, contains('date'));
         var responseDate = parser.parseHttpDate(response.headers['date']);
         expect(responseDate, date);
       });
     });
   });
+
+  group('server header', () {
+    test('defaults to "dart:io with Shelf"', () {
+      _scheduleServer(syncHandler);
+
+      return _scheduleGet().then((response) {
+        expect(response.headers, containsPair(HttpHeaders.SERVER, 'dart:io with Shelf'));

[nweiz, 2014/05/27 23:08:05]

Long line

[kevmoo, 2014/05/28 00:44:05]

Done.

+      });
+    });
+
+    test('deferres to response header when', () {

[nweiz, 2014/05/27 23:08:05]

"deferres" -> "defers", "response header when" -> "header in response"

[kevmoo, 2014/05/28 00:44:05]

Done.

+      _scheduleServer((request) {
+        return new Response.ok('test',
+            headers: {HttpHeaders.SERVER: 'myServer'});
+      });
+
+      return _scheduleGet().then((response) {
+        expect(response.headers, containsPair(HttpHeaders.SERVER, 'myServer'));
+      });
+    });
+  });
 }
 
 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();
   });
 }