pkg/shelf: added `url` and `scriptName` named params to Request.change

pkg/shelf/test/request_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.request_test;
 
 import 'dart:async';
 
 import 'package:shelf/shelf.dart';
 import 'package:unittest/unittest.dart';
@@ skipping 150 matching lines @@
       expect(copy.context, same(request.context));
       expect(copy.readAsString(), completion('hello, world'));
 
       controller.add(HELLO_BYTES);
       return new Future(() {
         controller
           ..add(WORLD_BYTES)
           ..close();
       });
     });
+
+    group('with just scriptName', () {
+      test('updates url if scriptName matches existing url', () {
+        var uri = Uri.parse('https://test.example.com/static/file.html');
+        var request = new Request('GET', uri);
+        var copy = request.change(scriptName: '/static');
+
+        expect(copy.scriptName, '/static');
+        expect(copy.url, Uri.parse('/file.html'));
+      });
+
+      test('throws if striptName does not match existing url', () {
+        var uri = Uri.parse('https://test.example.com/static/file.html');
+        var request = new Request('GET', uri);
+
+        expect(() => request.change(scriptName: '/nope'), throwsArgumentError);
+      });
+    });
+
+    test('url', () {
+      var uri = Uri.parse('https://test.example.com/static/file.html');
+      var request = new Request('GET', uri);
+      var copy = request.change(url: Uri.parse('/other_path/file.html'));
+
+      expect(copy.scriptName, '');
+      expect(copy.url, Uri.parse('/other_path/file.html'));
+    });
+
+    test('scriptName and url', () {
+      var uri = Uri.parse('https://test.example.com/static/file.html');
+      var request = new Request('GET', uri);
+      var copy = request.change(scriptName: '/dynamic',
+          url: Uri.parse('/other_path/file.html'));
+
+      expect(copy.scriptName, '/dynamic');
+      expect(copy.url, Uri.parse('/other_path/file.html'));
+    });
   });
 }