Add StreamChannel.withGuarantees and StreamChannelController.

test/stream_channel_controller_test.dart

+// Copyright (c) 2016, 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 'dart:async';
+
+import 'package:stream_channel/stream_channel.dart';
+import 'package:test/test.dart';
+
+import 'utils.dart';
+
+void main() {
+  group("asynchronously", () {
+    var controller;
+    setUp(() {
+      controller = new StreamChannelController();
+    });
+
+    test("forwards events from the local sink to the foreign stream", () {
+      controller.local.sink..add(1)..add(2)..add(3)..close();
+      expect(controller.foreign.stream.toList(), completion(equals([1, 2, 3])));
+    });
+
+    test("forwards events from the foreign sink to the local stream", () {
+      controller.foreign.sink..add(1)..add(2)..add(3)..close();
+      expect(controller.local.stream.toList(), completion(equals([1, 2, 3])));
+    });
+  });
+
+  group("synchronously", () {
+    var controller;
+    setUp(() {
+      controller = new StreamChannelController(sync: true);
+    });
+
+    test("synchronously forwards events from the local sink to the foreign "
+        "stream", () {
+      var receivedEvent = false;
+      var receivedError = false;
+      var receivedDone = false;
+      controller.foreign.stream.listen(expectAsync((event) {
+        expect(event, equals(1));
+        receivedEvent = true;
+      }), onError: expectAsync((error) {
+        expect(error, equals("oh no"));
+        receivedError = true;
+      }), onDone: expectAsync(() {
+        receivedDone = true;
+      }));
+
+      controller.local.sink.add(1);
+      expect(receivedEvent, isTrue);
+
+      controller.local.sink.addError("oh no");
+      expect(receivedError, isTrue);
+
+      controller.local.sink.close();
+      expect(receivedDone, isTrue);
+    });
+
+    test("synchronously forwards events from the foreign sink to the local "
+        "stream", () {
+      var receivedEvent = false;
+      var receivedError = false;
+      var receivedDone = false;
+      controller.local.stream.listen(expectAsync((event) {
+        expect(event, equals(1));
+        receivedEvent = true;
+      }), onError: expectAsync((error) {
+        expect(error, equals("oh no"));
+        receivedError = true;
+      }), onDone: expectAsync(() {
+        receivedDone = true;
+      }));
+
+      controller.foreign.sink.add(1);
+      expect(receivedEvent, isTrue);
+
+      controller.foreign.sink.addError("oh no");
+      expect(receivedError, isTrue);
+
+      controller.foreign.sink.close();
+      expect(receivedDone, isTrue);
+    });
+  });
+}