Make StreamController's unnamed constructor create a single-sub stream.

tests/lib/async/merge_stream_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 merging streams.
 library merge_stream_test;
 
 import "dart:async";
 import '../../../pkg/unittest/lib/unittest.dart';
 import 'event_helper.dart';
 
 testSupercedeStream() {
   { // Simple case of superceding lower priority streams.
-    StreamController s1 = new StreamController();
-    StreamController s2 = new StreamController();
-    StreamController s3 = new StreamController();
+    StreamController s1 = new StreamController.multiSubscription();
+    StreamController s2 = new StreamController.multiSubscription();
+    StreamController s3 = new StreamController.multiSubscription();
     Stream merge = new Stream.superceding([s1.stream, s2.stream, s3.stream]);
     Events expected = new Events()..add(1)..add(2)..add(3)..add(4)..close();
     Events actual = new Events.capture(merge);
     s1.add(1);
     s2.add(2);
     s1.add(1);  // Ignored.
     s2.add(3);
     s3.add(4);
     s2.add(3);  // Ignored.
     s3.close();
     Expect.listEquals(expected.events, actual.events);
   }
 
   { // Superceding more than one stream at a time.
-    StreamController s1 = new StreamController();
-    StreamController s2 = new StreamController();
-    StreamController s3 = new StreamController();
+    StreamController s1 = new StreamController.multiSubscription();
+    StreamController s2 = new StreamController.multiSubscription();
+    StreamController s3 = new StreamController.multiSubscription();
     Stream merge = new Stream.superceding([s1.stream, s2.stream, s3.stream]);
     Events expected = new Events()..add(1)..add(2)..close();
     Events actual = new Events.capture(merge);
     s1.add(1);
     s3.add(2);
     s1.add(1);  // Ignored.
     s2.add(1);  // Ignored.
     s3.close();
     Expect.listEquals(expected.events, actual.events);
   }
 
   { // Closing a stream before superceding it.
-    StreamController s1 = new StreamController();
-    StreamController s2 = new StreamController();
-    StreamController s3 = new StreamController();
+    StreamController s1 = new StreamController.multiSubscription();
+    StreamController s2 = new StreamController.multiSubscription();
+    StreamController s3 = new StreamController.multiSubscription();
     Stream merge = new Stream.superceding([s1.stream, s2.stream, s3.stream]);
     Events expected = new Events()..add(1)..add(2)..add(3)..close();
     Events actual = new Events.capture(merge);
     s1.add(1);
     s1.close();
     s3.close();
     s2.add(2);
     s2.add(3);
     s2.close();
     Expect.listEquals(expected.events, actual.events);
   }
 
   { // Errors from all non-superceded streams are forwarded.
-    StreamController s1 = new StreamController();
-    StreamController s2 = new StreamController();
-    StreamController s3 = new StreamController();
+    StreamController s1 = new StreamController.multiSubscription();
+    StreamController s2 = new StreamController.multiSubscription();
+    StreamController s3 = new StreamController.multiSubscription();
     Stream merge = new Stream.superceding([s1.stream, s2.stream, s3.stream]);
     Events expected =
         new Events()..add(1)..error("1")..error("2")..error("3")
                     ..add(3)..error("6")..add(4)..close();
     Events actual = new Events.capture(merge);
     s1.add(1);
     s1.signalError(new AsyncError("1"));
     s2.signalError(new AsyncError("2"));
     s3.signalError(new AsyncError("3"));
     s3.add(3);
     s1.signalError(new AsyncError("4"));
     s2.signalError(new AsyncError("5"));
     s3.signalError(new AsyncError("6"));
     s1.close();
     s2.close();
     s3.add(4);
     s3.close();
     Expect.listEquals(expected.events, actual.events);
   }
 
   test("Pausing on a superceding stream", () {
-    StreamController s1 = new StreamController();
-    StreamController s2 = new StreamController();
-    StreamController s3 = new StreamController();
+    StreamController s1 = new StreamController.multiSubscription();
+    StreamController s2 = new StreamController.multiSubscription();
+    StreamController s3 = new StreamController.multiSubscription();
     Stream merge = new Stream.superceding([s1.stream, s2.stream, s3.stream]);
     Events expected = new Events()..add(1)..add(2)..add(3);
     Events actual = new Events.capture(merge);
     s1.add(1);
     s2.add(2);
     s2.add(3);
     Expect.listEquals(expected.events, actual.events);
     actual.pause();  // Pauses the stream that feeds the actual Events.
     Events expected2 = expected.copy();
     expected..add(5)..add(6)..close();
     expected2..add(6)..close();
     s1.add(4);
     s2.add(5);  // May or may not arrive before '6' when resuming.
     s3.add(6);
     s3.close();
     actual.onDone(expectAsync0(() {
       if (expected.events.length == actual.events.length) {
         Expect.listEquals(expected.events, actual.events);
       } else {
         Expect.listEquals(expected2.events, actual.events);
       }
     }));
     actual.resume();
   });
 }
 
 void testCyclicStream() {
   test("Simple case of superceding lower priority streams", () {
-    StreamController s1 = new StreamController();
-    StreamController s2 = new StreamController();
-    StreamController s3 = new StreamController();
+    StreamController s1 = new StreamController.multiSubscription();
+    StreamController s2 = new StreamController.multiSubscription();
+    StreamController s3 = new StreamController.multiSubscription();
     Stream merge = new Stream.cyclic([s1.stream, s2.stream, s3.stream]);
     Events expected =
         new Events()..add(1)..add(2)..add(3)..add(4)..add(5)..add(6)..close();
     Events actual = new Events.capture(merge);
     Expect.isFalse(s1.isPaused);
     Expect.isTrue(s2.isPaused);
     Expect.isTrue(s3.isPaused);
     s3.add(3);
     s1.add(1);
     s1.add(4);
     s1.add(6);
     s1.close();
     s2.add(2);
     s2.add(5);
     s2.close();
     s3.close();
     actual.onDone(expectAsync0(() {
       Expect.listEquals(expected.events, actual.events);
     }));
   });
 
   test("Cyclic merge with errors", () {
-    StreamController s1 = new StreamController();
-    StreamController s2 = new StreamController();
-    StreamController s3 = new StreamController();
+    StreamController s1 = new StreamController.multiSubscription();
+    StreamController s2 = new StreamController.multiSubscription();
+    StreamController s3 = new StreamController.multiSubscription();
     Stream merge = new Stream.cyclic([s1.stream, s2.stream, s3.stream]);
     Events expected =
         new Events()..add(1)..error("1")..add(2)..add(3)..error("2")
                     ..add(4)..add(5)..error("3")..add(6)..close();
     Events actual = new Events.capture(merge);
     Expect.isFalse(s1.isPaused);
     Expect.isTrue(s2.isPaused);
     Expect.isTrue(s3.isPaused);
     s3.add(3);
     s3.signalError(new AsyncError("3"));  // Error just before a "done".
@@ skipping 10 matching lines @@
     actual.onDone(expectAsync0(() {
       Expect.listEquals(expected.events, actual.events);
     }));
   });
 }
 
 main() {
   testSupercedeStream();
   testCyclicStream();
 }