RealmResultsChanges.isCleared (#1265)

Deprecate isCleared for RealmResults.
Fixes #1189

CHANGELOG.md

@@ -16,11 +16,13 @@
     * Small (~5%) improvement when querying for a case insensitive match on a Mixed property that does not have an index.
 
 ### Fixed
+
 * Fixed a bug that may have resulted in arrays being in different orders on different devices (Core upgrade).
 * Fixed a crash when querying a mixed property with a string operator (contains/like/beginswith/endswith) or with case insensitivity (Core upgrade).
 * Querying for equality of a string on an indexed mixed property was returning case insensitive matches. For example querying for `myIndexedMixed == "Foo"` would incorrectly match on values of "foo" or "FOO" etc (Core upgrade).
 * Adding an index to a Mixed property on a non-empty table would crash with an assertion (Core upgrade).
 * `SyncSession.pause()` could hold a reference to the database open after shutting down the sync session, preventing users from being able to delete the realm (Core upgrade).
+* Fixed `RealmResultsChanges.isCleared` which was never set. It now returns `true` if the results collection is empty in the notification callback. This field is also marked as `deprecated` and will be removed in future. Use `RealmResultsChanges.results.isEmpty` instead.([#1265](https://github.com/realm/realm-dart/pull/1265)). ([#1278](https://github.com/realm/realm-dart/issues/1278)).
 
 ### Compatibility
 * Realm Studio: 13.0.0 or later.

lib/src/results.dart

@@ -137,6 +137,10 @@ class RealmResultsChanges<T extends Object?> extends RealmCollectionChanges {
   final RealmResults<T> results;
 
   RealmResultsChanges._(super.handle, this.results);
+
+  @override
+  @Deprecated("`isCleared` is deprecated. Use `isEmpty` of the results collection instead.")
+  bool get isCleared => results.isEmpty;
 }
 
 /// @nodoc

test/list_test.dart

@@ -1222,4 +1222,20 @@ Future<void> main([List<String>? args]) async {
       if (count > 1) fail('Should only receive one event');
     }
   });
+
+  test('List.asResults().isCleared notifications', () async {
+    final config = Configuration.local([Team.schema, Person.schema]);
+    final realm = getRealm(config);
+    final team = Team('Team 1', players: [Person('Alice'), Person('Bob')]);
+    realm.write(() => realm.add(team));
+    final playersAsResults = team.players.asResults();
+    expectLater(
+        playersAsResults.changes,
+        emitsInOrder(<Matcher>[
+          isA<RealmResultsChanges<Person>>().having((changes) => changes.inserted, 'inserted', <int>[]), // always an empty event on subscription
+          isA<RealmResultsChanges<Person>>().having((changes) => changes.isCleared, 'isCleared', true),
+        ]));
+    realm.write(() => team.players.clear());
+    expect(playersAsResults.length, 0);
+  });
 }

test/realm_set_test.dart

@@ -679,4 +679,24 @@ Future<void> main([List<String>? args]) async {
 
     expect(testSets.objectsSet.asResults(), cars);
   });
+
+  test('RealmSet.asResults().isCleared notifications', () {
+    var config = Configuration.local([TestRealmSets.schema, Car.schema]);
+    var realm = getRealm(config);
+
+    final cars = [Car("Tesla"), Car("Audi")];
+    final testSets = TestRealmSets(1)..objectsSet.addAll(cars);
+
+    realm.write(() {
+      realm.add(testSets);
+    });
+    final carsResult = testSets.objectsSet.asResults();
+    expectLater(
+        carsResult.changes,
+        emitsInOrder(<Matcher>[
+          isA<RealmResultsChanges<Object?>>().having((changes) => changes.inserted, 'inserted', <int>[]), // always an empty event on subscription
+          isA<RealmResultsChanges<Object?>>().having((changes) => changes.isCleared, 'isCleared', true),
+        ]));
+    realm.write(() => testSets.objectsSet.clear());
+  });
 }