Let StreamSubscription.cancel return a Future.

tests/lib/async/stream_state_test.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.
 
 // Test the event/callback protocol of the stream implementations.
 library stream_state_test;
 
 import "../../../pkg/unittest/lib/unittest.dart";
 import "stream_state_helper.dart";
 
@@ skipping 56 matching lines @@
        })
      ..expectDone()
      ..expectBroadcastCancelOpt()
      ..expectCancel(t.terminate);
     t..listen()..add(42);
   });
 
   test("$p-sub-data-unsubonerror", () {
     var t = asBroadcast ? new StreamProtocolTest.asBroadcast(sync: sync)
                         : new StreamProtocolTest(sync: sync);
-    t..expectListen()
-     ..expectBroadcastListenOpt()
-     ..expectData(42)
-     ..expectError("bad")
-     ..expectBroadcastCancelOpt()
-     ..expectCancel(t.terminate);
+    if (asBroadcast) {
+      t..expectListen()
+       ..expectBroadcastListenOpt()

[floitsch, 2013/10/12 18:53:57]

You should not need to use "Opt".
This is in the "asBroadcast" branch, so this listen should happen
unconditionally. Just remove the "Opt".

[Anders Johnsen, 2013/10/16 11:52:21]

Done.

+       ..expectData(42)
+       ..expectError("bad")
+       ..expectBroadcastCancelOpt()

[floitsch, 2013/10/12 18:53:57]

ditto.

[Anders Johnsen, 2013/10/16 11:52:21]

Done.

+       ..expectCancel(t.terminate);
+    } else {
+      t..expectListen()
+       ..expectBroadcastListenOpt()

[floitsch, 2013/10/12 18:53:57]

Remove, since we are in the non-broadcast branch.

[Anders Johnsen, 2013/10/16 11:52:21]

Done.

+       ..expectData(42)
+       ..expectCancel()
+       ..expectBroadcastCancelOpt()

[floitsch, 2013/10/12 18:53:57]

ditto.

[Anders Johnsen, 2013/10/16 11:52:21]

Done.

+       ..expectError("bad", t.terminate);
+    }
     t..listen(cancelOnError: true)
      ..add(42)
      ..error("bad")
      ..add(43)
      ..close();
   });

[Lasse Reichstein Nielsen, 2013/10/14 11:32:33]

I want to see tests where the close and the cancel are interleaved in every
possible way.

I want to see a cancel call inside all of a data event, an error event
(with/without cancelOnError), a done event.
And a close inside all of onListen, onPause, onResume (and, heck, onCancel).
Consider whether it makes sense to do a sub.cancel inside onListen, or a close
inside onData.
 

[Anders Johnsen, 2013/10/16 11:52:21]

Done.

 
   test("$p-sub-data-no-unsubonerror", () {
     var t = asBroadcast ? new StreamProtocolTest.asBroadcast(sync: sync)
                         : new StreamProtocolTest(sync: sync);
     t..expectListen()
      ..expectBroadcastListenOpt()
      ..expectData(42)
      ..expectError("bad")
      ..expectData(43)
      ..expectDone()
@@ skipping 19 matching lines @@
       t..expectPause();
     }
     t..expectDone()
      ..expectBroadcastCancelOpt()
      ..expectCancel(t.terminate);
     t..listen()
      ..add(42)
      ..close();
   });
 }