Make instances of HeaderValue and ContentType immutable

pkg/http/test/multipart_test.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2013, 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 multipart_test;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:utf';
 
 import 'package:unittest/unittest.dart';
@@ skipping 57 matching lines @@
     expect(request, bodyMatches('''
         --{{boundary}}
         content-disposition: form-data; name="field1"
 
         value1
         --{{boundary}}
         content-disposition: form-data; name="field2"
 
         value2
         --{{boundary}}
-        content-type: text/plain; charset=UTF-8
+        content-type: text/plain; charset=utf-8
         content-disposition: form-data; name="file1"; filename="filename1.txt"
 
         contents1
         --{{boundary}}
-        content-type: text/plain; charset=UTF-8
+        content-type: text/plain; charset=utf-8
         content-disposition: form-data; name="file2"
 
         contents2
         --{{boundary}}--
         '''));
   });
 
   test('with a unicode field name', () {
     var request = new http.MultipartRequest('POST', dummyUrl);
     request.fields['fïēld'] = 'value';
 
     expect(request, bodyMatches('''
         --{{boundary}}
         content-disposition: form-data; name="f%C3%AF%C4%93ld"
 
         value
         --{{boundary}}--
         '''));
   });
 
   test('with a unicode field value', () {
     var request = new http.MultipartRequest('POST', dummyUrl);
     request.fields['field'] = 'vⱥlūe';
 
     expect(request, bodyMatches('''
         --{{boundary}}
         content-disposition: form-data; name="field"
-        content-type: text/plain; charset=UTF-8
+        content-type: text/plain; charset=utf-8
 
         vⱥlūe
         --{{boundary}}--
         '''));
   });
 
   test('with a unicode filename', () {
     var request = new http.MultipartRequest('POST', dummyUrl);
     request.files.add(new http.MultipartFile.fromString('file', 'contents',
         filename: 'fïlēname.txt'));
 
     expect(request, bodyMatches('''
         --{{boundary}}
-        content-type: text/plain; charset=UTF-8
+        content-type: text/plain; charset=utf-8
         content-disposition: form-data; name="file"; filename="f%C3%AFl%C4%93name.txt"
 
         contents
         --{{boundary}}--
         '''));
   });
 
   test('with a string file with a content-type but no charset', () {
     var request = new http.MultipartRequest('POST', dummyUrl);
     var file = new http.MultipartFile.fromString('file', '{"hello": "world"}',
         contentType: new ContentType('application', 'json'));
     request.files.add(file);
 
     expect(request, bodyMatches('''
         --{{boundary}}
-        content-type: application/json; charset=UTF-8
+        content-type: application/json; charset=utf-8
         content-disposition: form-data; name="file"
 
         {"hello": "world"}
         --{{boundary}}--
         '''));
   });
 
   // TODO(nweiz): test creating a multipart file with a charset other than UTF-8
   // once issue 6284 is fixed.
 
@@ skipping 73 matching lines @@
         content-type: application/octet-stream
         content-disposition: form-data; name="file"; filename="test-file"
 
         hello
         --{{boundary}}--
         '''));
       }), completes);
     });
   });
 }