Make new StreamController be async by default.

tests/lib/async/stream_controller_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 basic StreamController and StreamController.singleSubscription.
 library stream_controller_test;
 
 import "package:expect/expect.dart";
 import 'dart:async';
 import 'event_helper.dart';
 
 testMultiController() {
   // Test normal flow.
-  var c = new StreamController();
+  var c = new StreamController(sync: true);
   Events expectedEvents = new Events()
       ..add(42)
       ..add("dibs")
       ..error("error!")
       ..error("error too!")
       ..close();
   Events actualEvents = new Events.capture(c.stream.asBroadcastStream());
   expectedEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test automatic unsubscription on error.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add(42)..error("error");
   actualEvents = new Events.capture(c.stream.asBroadcastStream(),
                                     cancelOnError: true);
   Events sentEvents =
       new Events()..add(42)..error("error")..add("Are you there?");
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test manual unsubscription.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add(42)..error("error")..add(37);
   actualEvents = new Events.capture(c.stream.asBroadcastStream(),
                                     cancelOnError: false);
   expectedEvents.replay(c);
   actualEvents.subscription.cancel();
   c.add("Are you there");  // Not sent to actualEvents.
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test filter.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()
     ..add("a string")..add("another string")..close();
   sentEvents = new Events()
     ..add("a string")..add(42)..add("another string")..close();
   actualEvents = new Events.capture(c.stream
     .asBroadcastStream()
     .where((v) => v is String));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test map.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add("abab")..error("error")..close();
   sentEvents = new Events()..add("ab")..error("error")..close();
   actualEvents = new Events.capture(c.stream
     .asBroadcastStream()
     .map((v) => "$v$v"));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test handleError.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add("ab")..error("[foo]");
   sentEvents = new Events()..add("ab")..error("foo")..add("ab")..close();
   actualEvents = new Events.capture(c.stream
     .asBroadcastStream()
     .handleError((error) {
         if (error is String) {
           // TODO(floitsch): this test originally changed the stacktrace.
           throw "[${error}]";
         }
       }), cancelOnError: true);
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // reduce is tested asynchronously and therefore not in this file.
 
   // Test expand
-  c = new StreamController();
+  c = new StreamController(sync: true);
   sentEvents = new Events()..add(3)..add(2)..add(4)..close();
   expectedEvents = new Events()..add(1)..add(2)..add(3)
                                ..add(1)..add(2)
                                ..add(1)..add(2)..add(3)..add(4)
                                ..close();
   actualEvents = new Events.capture(c.stream.asBroadcastStream().expand((v) {
     var l = [];
     for (int i = 0; i < v; i++) l.add(i + 1);
     return l;
   }));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test transform.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   sentEvents = new Events()..add("a")..error(42)..add("b")..close();
   expectedEvents =
       new Events()..error("a")..add(42)..error("b")..add("foo")..close();
   actualEvents = new Events.capture(c.stream.asBroadcastStream().transform(
       new StreamTransformer(
           handleData: (v, s) { s.addError(v); },
           handleError: (e, s) { s.add(e); },
           handleDone: (s) {
 
             s.add("foo");
 
             s.close();
 
           })));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test multiple filters.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   sentEvents = new Events()..add(42)
                            ..add("snugglefluffy")
                            ..add(7)
                            ..add("42")
                            ..error("not FormatException")  // Unsubscribes.
                            ..close();
   expectedEvents = new Events()..add(42)..error("not FormatException");
   actualEvents = new Events.capture(
       c.stream.asBroadcastStream().where((v) => v is String)
        .map((v) => int.parse(v))
        .handleError((error) {
           if (error is! FormatException) throw error;
         })
        .where((v) => v > 10),
       cancelOnError: true);
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test subscription changes while firing.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   var sink = c.sink;
   var stream = c.stream.asBroadcastStream();
   var counter = 0;
   var subscription = stream.listen(null);
   subscription.onData((data) {
     counter += data;
     subscription.cancel();
     stream.listen((data) {
       counter += 10 * data;
     });
     var subscription2 = stream.listen(null);
     subscription2.onData((data) {
       counter += 100 * data;
       if (data == 4) subscription2.cancel();
     });
   });
   sink.add(1); // seen by stream 1
   sink.add(2); // seen by stream 10 and 100
   sink.add(3); // -"-
   sink.add(4); // -"-
   sink.add(5); // seen by stream 10
   Expect.equals(1 + 20 + 200 + 30 + 300 + 40 + 400 + 50, counter);
 }
 
 testSingleController() {
   // Test normal flow.
-  var c = new StreamController();
+  var c = new StreamController(sync: true);
   Events expectedEvents = new Events()
       ..add(42)
       ..add("dibs")
       ..error("error!")
       ..error("error too!")
       ..close();
   Events actualEvents = new Events.capture(c.stream);
   expectedEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test automatic unsubscription on error.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add(42)..error("error");
   actualEvents = new Events.capture(c.stream, cancelOnError: true);
   Events sentEvents =
       new Events()..add(42)..error("error")..add("Are you there?");
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test manual unsubscription.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add(42)..error("error")..add(37);
   actualEvents = new Events.capture(c.stream, cancelOnError: false);
   expectedEvents.replay(c);
   actualEvents.subscription.cancel();
   c.add("Are you there");  // Not sent to actualEvents.
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test filter.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()
     ..add("a string")..add("another string")..close();
   sentEvents = new Events()
     ..add("a string")..add(42)..add("another string")..close();
   actualEvents = new Events.capture(c.stream.where((v) => v is String));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test map.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add("abab")..error("error")..close();
   sentEvents = new Events()..add("ab")..error("error")..close();
   actualEvents = new Events.capture(c.stream.map((v) => "$v$v"));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test handleError.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add("ab")..error("[foo]");
   sentEvents = new Events()..add("ab")..error("foo")..add("ab")..close();
   actualEvents = new Events.capture(c.stream.handleError((error) {
         if (error is String) {
           // TODO(floitsch): this error originally changed the stack trace.
           throw "[${error}]";
         }
       }), cancelOnError: true);
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // reduce is tested asynchronously and therefore not in this file.
 
   // Test expand
-  c = new StreamController();
+  c = new StreamController(sync: true);
   sentEvents = new Events()..add(3)..add(2)..add(4)..close();
   expectedEvents = new Events()..add(1)..add(2)..add(3)
                                ..add(1)..add(2)
                                ..add(1)..add(2)..add(3)..add(4)
                                ..close();
   actualEvents = new Events.capture(c.stream.expand((v) {
     var l = [];
     for (int i = 0; i < v; i++) l.add(i + 1);
     return l;
   }));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // test contains.
   {
-    c = new StreamController();
+    c = new StreamController(sync: true);
     // Error after match is not important.
     sentEvents = new Events()..add("a")..add("x")..error("FAIL")..close();
     Future<bool> contains = c.stream.contains("x");
     contains.then((var c) {
       Expect.isTrue(c);
     });
     sentEvents.replay(c);
   }
 
   {
-    c = new StreamController();
+    c = new StreamController(sync: true);
     // Not matching is ok.
     sentEvents = new Events()..add("a")..add("x")..add("b")..close();
     Future<bool> contains = c.stream.contains("y");
     contains.then((var c) {
       Expect.isFalse(c);
     });
     sentEvents.replay(c);
   }
 
   {
-    c = new StreamController();
+    c = new StreamController(sync: true);
     // Error before match makes future err.
     sentEvents = new Events()..add("a")..error("FAIL")..add("b")..close();
     Future<bool> contains = c.stream.contains("b");
     contains.then((var c) {
       Expect.fail("no value expected");
     }).catchError((error) {
       Expect.equals("FAIL", error);
     });
     sentEvents.replay(c);
   }
 
   // Test transform.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   sentEvents = new Events()..add("a")..error(42)..add("b")..close();
   expectedEvents =
       new Events()..error("a")..add(42)..error("b")..add("foo")..close();
   actualEvents = new Events.capture(c.stream.transform(
       new StreamTransformer(
           handleData: (v, s) { s.addError(v); },
           handleError: (e, s) { s.add(e); },
           handleDone: (s) {
             s.add("foo");
             s.close();
           })));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test multiple filters.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   sentEvents = new Events()..add(42)
                            ..add("snugglefluffy")
                            ..add(7)
                            ..add("42")
                            ..error("not FormatException")  // Unsubscribes.
                            ..close();
   expectedEvents = new Events()..add(42)..error("not FormatException");
   actualEvents = new Events.capture(
       c.stream.where((v) => v is String)
        .map((v) => int.parse(v))
        .handleError((error) {
           if (error is! FormatException) throw error;
         })
        .where((v) => v > 10),
       cancelOnError: true);
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
   // Test that only one subscription is allowed.
-  c = new StreamController();
+  c = new StreamController(sync: true);
   var sink = c.sink;
   var stream = c.stream;
   var counter = 0;
   var subscription = stream.listen((data) { counter += data; });
   Expect.throws(() => stream.listen(null), (e) => e is StateError);
   sink.add(1);
   Expect.equals(1, counter);
   c.close();
 }
 
 testExtraMethods() {
   Events sentEvents = new Events()..add(1)..add(2)..add(3)..close();
 
-  var c = new StreamController();
+  var c = new StreamController(sync: true);
   Events expectedEvents = new Events()..add(3)..close();
   Events actualEvents = new Events.capture(c.stream.skip(2));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..close();
   actualEvents = new Events.capture(c.stream.skip(3));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..close();
   actualEvents = new Events.capture(c.stream.skip(7));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = sentEvents;
   actualEvents = new Events.capture(c.stream.skip(0));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
 
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add(3)..close();
   actualEvents = new Events.capture(c.stream.skipWhile((x) => x <= 2));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
 
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add(2)..add(3)..close();
   actualEvents = new Events.capture(c.stream.skipWhile((x) => x <= 1));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
 
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add(1)..add(2)..add(3)..close();
   actualEvents = new Events.capture(c.stream.skipWhile((x) => false));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
 
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add(1)..add(2)..close();
   actualEvents = new Events.capture(c.stream.take(2));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
 
-  c = new StreamController();
+  c = new StreamController(sync: true);
   expectedEvents = new Events()..add(1)..add(2)..close();
   actualEvents = new Events.capture(c.stream.takeWhile((x) => x <= 2));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
 
-  c = new StreamController();
+  c = new StreamController(sync: true);
   sentEvents = new Events()
       ..add(1)..add(1)..add(2)..add(1)..add(2)..add(2)..add(2)..close();
   expectedEvents = new Events()
       ..add(1)..add(2)..add(1)..add(2)..close();
   actualEvents = new Events.capture(c.stream.distinct());
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 
 
-  c = new StreamController();
+  c = new StreamController(sync: true);
   sentEvents = new Events()
       ..add(5)..add(6)..add(4)..add(6)..add(8)..add(3)..add(4)..add(1)..close();
   expectedEvents = new Events()
       ..add(5)..add(4)..add(3)..add(1)..close();
   // Use 'distinct' as a filter with access to the previously emitted event.
   actualEvents = new Events.capture(c.stream.distinct((a, b) => a < b));
   sentEvents.replay(c);
   Expect.listEquals(expectedEvents.events, actualEvents.events);
 }
 
 testClosed() {
-  StreamController c = new StreamController();
+  StreamController c = new StreamController(sync: true);
   Expect.isFalse(c.isClosed);
   c.add(42);
   Expect.isFalse(c.isClosed);
   c.addError("bad");
   Expect.isFalse(c.isClosed);
   c.close();
   Expect.isTrue(c.isClosed);
 }
 
 main() {
   testMultiController();
   testSingleController();
   testExtraMethods();
   testClosed();
 }