package:observe fix various api issues

pkg/observe/test/observable_list_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.
 
 import 'dart:async';
 import 'package:observe/observe.dart';
 import 'package:unittest/unittest.dart';
 import 'observe_test_utils.dart';
 
 main() {
   // TODO(jmesserly): need all standard List API tests.
 
   StreamSubscription sub;
 
   sharedTearDown() { sub.cancel(); }
 
   group('observe length', () {
 
     ObservableList list;
     List<ChangeRecord> changes;
 
     setUp(() {
       list = toObservable([1, 2, 3]);
       changes = null;
       sub = list.changes.listen((records) {
-        changes = records.where((r) => r.changes(#length)).toList();
+        changes = getPropertyChangeRecords(records, #length);
       });
     });
 
     tearDown(sharedTearDown);
 
     observeTest('add changes length', () {
       list.add(4);
       expect(list, [1, 2, 3, 4]);
       performMicrotaskCheckpoint();
-      expectChanges(changes, [_lengthChange]);
+      expectChanges(changes, [_lengthChange(list, 3, 4)]);
     });
 
     observeTest('removeObject', () {
       list.remove(2);
       expect(list, orderedEquals([1, 3]));
 
       performMicrotaskCheckpoint();
-      expectChanges(changes, [_lengthChange]);
+      expectChanges(changes, [_lengthChange(list, 3, 2)]);
     });
 
     observeTest('removeRange changes length', () {
       list.add(4);
       list.removeRange(1, 3);
       expect(list, [1, 4]);
       performMicrotaskCheckpoint();
-      expectChanges(changes, [_lengthChange]);
+      expectChanges(changes, [_lengthChange(list, 3, 2)]);
     });
 
     observeTest('length= changes length', () {
       list.length = 5;
       expect(list, [1, 2, 3, null, null]);
       performMicrotaskCheckpoint();
-      expectChanges(changes, [_lengthChange]);
+      expectChanges(changes, [_lengthChange(list, 3, 5)]);
     });
 
     observeTest('[]= does not change length', () {
       list[2] = 9000;
       expect(list, [1, 2, 9000]);
       performMicrotaskCheckpoint();
       expectChanges(changes, []);
     });
 
     observeTest('clear changes length', () {
       list.clear();
       expect(list, []);
       performMicrotaskCheckpoint();
-      expectChanges(changes, [_lengthChange]);
+      expectChanges(changes, [_lengthChange(list, 3, 0)]);
     });
   });
 
   group('observe index', () {
     ObservableList list;
     List<ChangeRecord> changes;
 
     setUp(() {
       list = toObservable([1, 2, 3]);
       changes = null;
       sub = list.changes.listen((records) {
-        changes = records.where((r) => r.changes(1)).toList();
+        changes = getListChangeRecords(records, 1);
       });
     });
 
     tearDown(sharedTearDown);
 
     observeTest('add does not change existing items', () {
       list.add(4);
       expect(list, [1, 2, 3, 4]);
       performMicrotaskCheckpoint();
       expectChanges(changes, []);
@@ skipping 93 matching lines @@
       expectChanges(records, null);
     });
 
     observeTest('add', () {
       list.add(5);
       list.add(6);
       expect(list, orderedEquals([1, 2, 3, 1, 3, 4, 5, 6]));
 
       performMicrotaskCheckpoint();
       expectChanges(records, [
-        _lengthChange,
+        _lengthChange(list, 6, 8),
         _change(6, addedCount: 2)
       ]);
     });
 
     observeTest('[]=', () {
       list[1] = list.last;
       expect(list, orderedEquals([1, 4, 3, 1, 3, 4]));
 
       performMicrotaskCheckpoint();
       expectChanges(records, [ _change(1, addedCount: 1, removedCount: 1) ]);
     });
 
     observeTest('removeLast', () {
       expect(list.removeLast(), 4);
       expect(list, orderedEquals([1, 2, 3, 1, 3]));
 
       performMicrotaskCheckpoint();
       expectChanges(records, [
-        _lengthChange,
+        _lengthChange(list, 6, 5),
         _change(5, removedCount: 1)
       ]);
     });
 
     observeTest('removeRange', () {
       list.removeRange(1, 4);
       expect(list, orderedEquals([1, 3, 4]));
 
       performMicrotaskCheckpoint();
       expectChanges(records, [
-        _lengthChange,
+        _lengthChange(list, 6, 3),
         _change(1, removedCount: 3),
       ]);
     });
 
     observeTest('sort', () {
       list.sort((x, y) => x - y);
       expect(list, orderedEquals([1, 1, 2, 3, 3, 4]));
 
       performMicrotaskCheckpoint();
       expectChanges(records, [
         _change(1, addedCount: 5, removedCount: 5),
       ]);
     });
 
     observeTest('clear', () {
       list.clear();
       expect(list, []);
 
       performMicrotaskCheckpoint();
       expectChanges(records, [
-        _lengthChange,
+        _lengthChange(list, 6, 0),
         _change(0, removedCount: 6)
       ]);
     });
   });
 }
 
-final _lengthChange = new PropertyChangeRecord(#length);
+_lengthChange(list, int oldValue, int newValue) =>
+    new PropertyChangeRecord(list, #length, oldValue, newValue);
 
 _change(index, {removedCount: 0, addedCount: 0}) => new ListChangeRecord(
     index, removedCount: removedCount, addedCount: addedCount);