Add transformer support to Converters.

tests/lib/convert/json_unicode_tests.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 json_unicode_tests;
+import 'unicode_tests.dart';
+
+const _QUOTE = 0x22;  // "
+const _COLON = 0x3a;  // :
+const _COMMA = 0x2c;  // ,
+const _BRACE_OPEN = 0x7b;  // {
+const _BRACE_CLOSE = 0x7d;  // }
+const _BRACKET_OPEN = 0x5b;  // [
+const _BRACKET_CLOSE = 0x5d;  // ]
+
+_expandUnicodeTests() {
+  return UNICODE_TESTS.expand((test) {
+    // The unicode test will be a string (possibly) containing unicode
+    // characters. It also contains the empty string.
+    // It must not contain a double-quote '"'.
+    assert(!test.contains('"'));
+
+    var bytes = test[0];
+    var string = test[1];
+
+    // expanded will hold all tests that are generated from the unicode test.
+    var expanded = [];
+
+    // Put the string into quotes.
+    // For example: 'abcd' -> '"abcd"'.
+    var inQuotesBytes = [];
+    inQuotesBytes.add(_QUOTE);
+    inQuotesBytes.addAll(bytes);
+    inQuotesBytes.add(_QUOTE);
+    expanded.add([inQuotesBytes, string]);
+
+    // Put the quoted string into a triple nested list.
+    // For example: 'abcd' -> '[[["abcd"]]]'.
+    var listExpected = [[[string]]];
+    var inListBytes = [];
+    inListBytes.addAll([_BRACKET_OPEN, _BRACKET_OPEN, _BRACKET_OPEN]);
+    inListBytes.addAll(inQuotesBytes);
+    inListBytes.addAll([_BRACKET_CLOSE, _BRACKET_CLOSE, _BRACKET_CLOSE]);
+    expanded.add([inListBytes, listExpected]);
+
+    // Put the quoted string into a triple nested list and duplicate that
+    // list three times.
+    // For example: 'abcd' -> '[[[["abcd"]]],[[["abcd"]]],[[["abcd"]]]]'.
+    var listLongerExpected = [listExpected, listExpected, listExpected];
+    var listLongerBytes = [];
+    listLongerBytes.add(_BRACKET_OPEN);
+    listLongerBytes.addAll(inListBytes);
+    listLongerBytes.add(_COMMA);
+    listLongerBytes.addAll(inListBytes);
+    listLongerBytes.add(_COMMA);
+    listLongerBytes.addAll(inListBytes);
+    listLongerBytes.add(_BRACKET_CLOSE);
+    expanded.add([listLongerBytes, listLongerExpected]);
+
+    // Put the previous strings/lists into a map.
+    // For example:
+    //    'abcd' -> '{"abcd":[[[["abcd"]]],[[["abcd"]]],[[["abcd"]]]]}'.
+    var mapExpected = new Map();
+    mapExpected[string] = listLongerExpected;
+    var mapBytes = [];
+    mapBytes.add(_BRACE_OPEN);
+    mapBytes.addAll(inQuotesBytes);
+    mapBytes.add(_COLON);
+    mapBytes.addAll(listLongerBytes);
+    mapBytes.add(_BRACE_CLOSE);
+    expanded.add([mapBytes, mapExpected]);
+
+    return expanded;
+  }).toList();
+}
+
+final JSON_UNICODE_TESTS = _expandUnicodeTests();