Revert "Return futures on Stream.cancel when possible."

tests/lib/async/stream_subscription_cancel_test.dart

Index: tests/lib/async/stream_subscription_cancel_test.dart
diff --git a/tests/lib/async/stream_subscription_cancel_test.dart b/tests/lib/async/stream_subscription_cancel_test.dart
index 48649b2717df0566aada0e9b0050562324910f44..d6c6987545fcc04568eaed5f881e8c08d8a37f94 100644
--- a/tests/lib/async/stream_subscription_cancel_test.dart
+++ b/tests/lib/async/stream_subscription_cancel_test.dart
@@ -27,22 +27,17 @@ void main() {
   test('subscription.cancel after close', () {
     var completer = new Completer();
     StreamController controller = new StreamController(
-        onCancel: () {
-          completer.complete();
-          return completer.future;
-        });
+        onCancel: completer.complete);
 
     controller.close();
 
-    var completer2 = new Completer();
     var sub;
     void onDone() {
-      sub.cancel().then(completer2.complete);
+      expect(sub.cancel(), isNull);
     }
 
     sub = controller.stream.listen(null, onDone: onDone);
     expect(completer.future, completes);
-    expect(completer2.future, completes);
   });
 
   test('subscription.cancel after error', () {
@@ -140,183 +135,4 @@ void main() {
       .cancel();
     expect(doneCompleter.future, completion(equals(true)));
   });
-
-  test('subscription.cancel through map', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var future = controller.stream.map((x) => x).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
-
-  test('subscription.cancel through asyncMap', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var future = controller.stream.asyncMap((x) => x).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
-
-  test('subscription.cancel through asyncExpand', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var future = controller.stream.asyncExpand((x) => x).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
-
-  test('subscription.cancel through handleError', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var future = controller.stream.handleError((x) => x).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
-
-  test('subscription.cancel through skip', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var future = controller.stream.skip(1).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
-
-  test('subscription.cancel through take', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var future = controller.stream.take(1).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
-
-  test('subscription.cancel through skipWhile', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var future = controller.stream.skipWhile((x) => true).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
-
-  test('subscription.cancel through takeWhile', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var future = controller.stream.takeWhile((x) => true).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
-
-  test('subscription.cancel through timeOut', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var duration = const Duration(hours: 5);
-    var future = controller.stream.timeout(duration).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
-
-  test('subscription.cancel through transform', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var transformer =
-        new StreamTransformer.fromHandlers(handleData: (x, y) {});
-    var future = controller.stream.transform(transformer).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
-
-  test('subscription.cancel through where', () {
-    var completer = new Completer();
-    StreamController controller = new StreamController(
-        onCancel: () => completer.future);
-
-    bool done = false;
-    var future = controller.stream.where((x) => true).listen(null).cancel();
-
-    expect(future.then((_) => done = true), completion(equals(true)));
-
-    Timer.run(() {
-      expect(done, isFalse);
-      completer.complete();
-    });
-  });
 }