Add UTF-8 encoder.

tests/lib/convert/utf8_encode_test.dart

+// 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 utf8_test;
+import "package:expect/expect.dart";
+import 'dart:convert';
+
+// Google favorite: "Îñţérñåţîöñåļîžåţîờñ".
+const INTER_BYTES = const [0xc3, 0x8e, 0xc3, 0xb1, 0xc5, 0xa3, 0xc3, 0xa9, 0x72,
+                           0xc3, 0xb1, 0xc3, 0xa5, 0xc5, 0xa3, 0xc3, 0xae, 0xc3,
+                           0xb6, 0xc3, 0xb1, 0xc3, 0xa5, 0xc4, 0xbc, 0xc3, 0xae,
+                           0xc5, 0xbe, 0xc3, 0xa5, 0xc5, 0xa3, 0xc3, 0xae, 0xe1,
+                           0xbb, 0x9d, 0xc3, 0xb1];
+const INTER_STRING = "Îñţérñåţîöñåļîžåţîờñ";
+
+// Blueberry porridge in Danish: "blåbærgrød".
+const BLUEBERRY_BYTES = const [0x62, 0x6c, 0xc3, 0xa5, 0x62, 0xc3, 0xa6, 0x72,
+                               0x67, 0x72, 0xc3, 0xb8, 0x64];
+const BLUEBERRY_STRING = "blåbærgrød";
+
+// "சிவா அணாமாைல", that is "Siva Annamalai" in Tamil.
+const SIVA_BYTES1 = const [0xe0, 0xae, 0x9a, 0xe0, 0xae, 0xbf, 0xe0, 0xae, 0xb5,
+                           0xe0, 0xae, 0xbe, 0x20, 0xe0, 0xae, 0x85, 0xe0, 0xae,
+                           0xa3, 0xe0, 0xae, 0xbe, 0xe0, 0xae, 0xae, 0xe0, 0xae,
+                           0xbe, 0xe0, 0xaf, 0x88, 0xe0, 0xae, 0xb2];
+const SIVA_STRING1 = "சிவா அணாமாைல";
+
+// "िसवा अणामालै", that is "Siva Annamalai" in Devanagari.
+const SIVA_BYTES2 = const [0xe0, 0xa4, 0xbf, 0xe0, 0xa4, 0xb8, 0xe0, 0xa4, 0xb5,
+                           0xe0, 0xa4, 0xbe, 0x20, 0xe0, 0xa4, 0x85, 0xe0, 0xa4,
+                           0xa3, 0xe0, 0xa4, 0xbe, 0xe0, 0xa4, 0xae, 0xe0, 0xa4,
+                           0xbe, 0xe0, 0xa4, 0xb2, 0xe0, 0xa5, 0x88];
+const SIVA_STRING2 = "िसवा अणामालै";
+
+// DESERET CAPITAL LETTER BEE, unicode 0x10412(0xD801+0xDC12)
+// UTF-8: F0 90 90 92
+const BEE_BYTES = const [0xf0, 0x90, 0x90, 0x92];
+const BEE_STRING = "𐐒";
+
+const DIGIT_BYTES = const [ 0x35 ];
+const DIGIT_STRING = "5";
+
+const ASCII_BYTES = const [ 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+                            0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
+                            0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
+                            0x79, 0x7A ];
+const ASCII_STRING = "abcdefghijklmnopqrstuvwxyz";
+
+const TESTS = const [
+    const [ const [], "" ],
+    const [ INTER_BYTES, INTER_STRING ],
+    const [ BLUEBERRY_BYTES, BLUEBERRY_STRING ],
+    const [ SIVA_BYTES1, SIVA_STRING1 ],
+    const [ SIVA_BYTES2, SIVA_STRING2 ],
+    const [ BEE_BYTES, BEE_STRING ],
+    const [ DIGIT_BYTES, DIGIT_STRING ],
+    const [ ASCII_BYTES, ASCII_STRING ]];
+
+List<int> encode(String str) => new Utf8Encoder().convert(str);
+List<int> encode2(String str) => UTF8.encode(str);
+
+main() {
+  Expect.equals(2, BEE_STRING.length);
+  var tests = TESTS.expand((test) {
+    var bytes = test[0];
+    var string = test[1];
+    var longBytes = [];
+    var longString = "";
+    for (int i = 0; i < 100; i++) {
+      longBytes.addAll(bytes);
+      longString += string;
+    }
+    return [test, [longBytes, longString]];
+  });
+  for (var test in tests) {
+    List<int> bytes = test[0];
+    String string = test[1];
+    Expect.listEquals(bytes, encode(string));
+    Expect.listEquals(bytes, encode2(string));
+  }
+}