Add transformer support to Converters.

tests/lib/convert/streamed_conversion_utf8_decode_test.dart

Index: tests/lib/convert/streamed_conversion_utf8_decode_test.dart
diff --git a/tests/lib/convert/streamed_conversion_utf8_decode_test.dart b/tests/lib/convert/streamed_conversion_utf8_decode_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..e29d384ee03baf06e4fcb028324cac3721f0c12c
--- /dev/null
+++ b/tests/lib/convert/streamed_conversion_utf8_decode_test.dart
@@ -0,0 +1,66 @@
+// 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.
+
+import "package:expect/expect.dart";
+import 'dart:async';
+import 'dart:convert';
+import 'unicode_tests.dart';
+import '../../async_helper.dart';
+
+Stream<String> decode(List<int> bytes, int chunkSize) {
+  var controller;
+  controller = new StreamController(onListen: () {
+    int i = 0;
+    while (i < bytes.length) {
+      List nextChunk = [];
+      for (int j = 0; j < chunkSize; j++) {
+        if (i < bytes.length) {
+          nextChunk.add(bytes[i]);
+          i++;
+        }
+      }
+      controller.add(nextChunk);
+    }
+    controller.close();
+  });
+  return controller.stream.transform(UTF8.decoder);
+}
+
+testUnpaused(String expected, Stream stream) {
+  asyncStart();
+  stream.toList().then((list) {
+    StringBuffer buffer = new StringBuffer();
+    buffer.writeAll(list);
+    Expect.stringEquals(expected, buffer.toString());
+    asyncEnd();
+  });
+}
+
+testWithPauses(String expected, Stream stream) {
+  asyncStart();
+  StringBuffer buffer = new StringBuffer();
+  var sub;
+  sub = stream.listen((x) {
+    buffer.write(x);
+    sub.pause(new Future.delayed(Duration.ZERO));
+  }, onDone: () {
+    Expect.stringEquals(expected, buffer.toString());
+    asyncEnd();
+  });
+}
+
+main() {
+  for (var test in UNICODE_TESTS) {
+    var bytes = test[0];
+    var expected = test[1];
+    testUnpaused(expected, decode(bytes, 1));
+    testWithPauses(expected, decode(bytes, 1));
+    testUnpaused(expected, decode(bytes, 2));
+    testWithPauses(expected, decode(bytes, 2));
+    testUnpaused(expected, decode(bytes, 3));
+    testWithPauses(expected, decode(bytes, 3));
+    testUnpaused(expected, decode(bytes, 4));
+    testWithPauses(expected, decode(bytes, 4));
+  }
+}