Source Code added

mobile/test/modules/utils/diff_test.dart

@@ -0,0 +1,50 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:immich_mobile/utils/diff.dart';
+
+void main() {
+  final List<int> listA = [1, 2, 3, 4, 6];
+  final List<int> listB = [1, 3, 5, 7];
+
+  group('Test grouped', () {
+    test('test partial overlap', () async {
+      final List<int> onlyInA = [];
+      final List<int> onlyInB = [];
+      final List<int> inBoth = [];
+      final changes = await diffSortedLists(
+        listA,
+        listB,
+        compare: (int a, int b) => a.compareTo(b),
+        both: (int a, int b) {
+          inBoth.add(b);
+          return false;
+        },
+        onlyFirst: (int a) => onlyInA.add(a),
+        onlySecond: (int b) => onlyInB.add(b),
+      );
+      expect(changes, true);
+      expect(onlyInA, [2, 4, 6]);
+      expect(onlyInB, [5, 7]);
+      expect(inBoth, [1, 3]);
+    });
+    test('test partial overlap sync', () {
+      final List<int> onlyInA = [];
+      final List<int> onlyInB = [];
+      final List<int> inBoth = [];
+      final changes = diffSortedListsSync(
+        listA,
+        listB,
+        compare: (int a, int b) => a.compareTo(b),
+        both: (int a, int b) {
+          inBoth.add(b);
+          return false;
+        },
+        onlyFirst: (int a) => onlyInA.add(a),
+        onlySecond: (int b) => onlyInB.add(b),
+      );
+      expect(changes, true);
+      expect(onlyInA, [2, 4, 6]);
+      expect(onlyInB, [5, 7]);
+      expect(inBoth, [1, 3]);
+    });
+  });
+}