Migrate async tests to strong

tests/lib_strong/async/stream_single_test.dart

+// Copyright (c) 2011, 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.
+
+// Test the Stream.single method.
+library stream_single_test;
+
+import "package:expect/expect.dart";
+import 'dart:async';
+import 'package:unittest/unittest.dart';
+import 'event_helper.dart';
+
+main() {
+  test("single", () {
+    StreamController c = new StreamController(sync: true);
+    Future f = c.stream.single;
+    f.then(expectAsync((v) { Expect.equals(42, v);}));
+    new Events.fromIterable([42]).replay(c);
+  });
+
+  test("single empty", () {
+    StreamController c = new StreamController(sync: true);
+    Future f = c.stream.single;
+    f.catchError(expectAsync((error) { Expect.isTrue(error is StateError); }));
+    new Events.fromIterable([]).replay(c);
+  });
+
+  test("single error", () {
+    StreamController c = new StreamController(sync: true);
+    Future f = c.stream.single;
+    f.catchError(expectAsync((error) { Expect.equals("error", error); }));
+    Events errorEvents = new Events()..error("error")..close();
+    errorEvents.replay(c);
+  });
+
+  test("single error 2", () {
+    StreamController c = new StreamController(sync: true);
+    Future f = c.stream.single;
+    f.catchError(expectAsync((error) { Expect.equals("error", error); }));
+    Events errorEvents = new Events()..error("error")..error("error2")..close();
+    errorEvents.replay(c);
+  });
+
+  test("single error 3", () {
+    StreamController c = new StreamController(sync: true);
+    Future f = c.stream.single;
+    f.catchError(expectAsync((error) { Expect.equals("error", error); }));
+    Events errorEvents = new Events()..add(499)..error("error")..close();
+    errorEvents.replay(c);
+  });
+}