Fix detecting changes in sync options

packages/powersync_core/lib/src/sync/options.dart

@@ -47,9 +47,9 @@ extension type ResolvedSyncOptions(SyncOptions source) {
       params: other.params ?? params,
     );
 
-    final didChange = !_mapEquality.equals(other.params, params) ||
-        other.crudThrottleTime != crudThrottleTime ||
-        other.retryDelay != retryDelay;
+    final didChange = !_mapEquality.equals(newOptions.params, params) ||
+        newOptions.crudThrottleTime != crudThrottleTime ||
+        newOptions.retryDelay != retryDelay;
     return (ResolvedSyncOptions(newOptions), didChange);
   }
 

packages/powersync_core/test/sync/options_test.dart

@@ -0,0 +1,37 @@
+import 'package:powersync_core/src/sync/options.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('sync options', () {
+    test('can merge with changes', () {
+      final a = ResolvedSyncOptions(SyncOptions(
+        params: {'client': 'a'},
+        crudThrottleTime: const Duration(seconds: 1),
+      ));
+
+      final (b, didChange) = a.applyFrom(SyncOptions(
+        params: {'client': 'a'},
+        retryDelay: const Duration(seconds: 1),
+      ));
+
+      expect(b.params, {'client': 'a'});
+      expect(b.crudThrottleTime, const Duration(seconds: 1));
+      expect(b.retryDelay, const Duration(seconds: 1));
+      expect(didChange, isTrue);
+    });
+
+    test('can merge without changes', () {
+      final a = ResolvedSyncOptions(SyncOptions(
+        params: {'client': 'a'},
+        crudThrottleTime: const Duration(seconds: 1),
+      ));
+
+      final (_, didChange) = a.applyFrom(SyncOptions(
+        // This is the default, so no change from a
+        retryDelay: const Duration(seconds: 5),
+      ));
+
+      expect(didChange, isFalse);
+    });
+  });
+}