Source Code added

mobile/test/modules/extensions/datetime_extensions_test.dart

@@ -0,0 +1,46 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:immich_mobile/extensions/datetime_extensions.dart';
+import 'package:intl/date_symbol_data_local.dart';
+
+void main() {
+  setUpAll(() async {
+    await initializeDateFormatting();
+  });
+
+  group('DateRangeFormatting.formatDateRange', () {
+    final currentYear = DateTime.now().year;
+
+    test('returns single date format for this year', () {
+      final date = DateTime(currentYear, 8, 28); // Aug 28 this year
+      final result = DateRangeFormatting.formatDateRange(date, date, null);
+      expect(result, 'Aug 28');
+    });
+
+    test('returns single date format for other year', () {
+      final date = DateTime(2023, 8, 28); // Aug 28, 2023
+      final result = DateRangeFormatting.formatDateRange(date, date, null);
+      expect(result, 'Aug 28, 2023');
+    });
+
+    test('returns date range format for this year', () {
+      final startDate = DateTime(currentYear, 3, 23); // Mar 23
+      final endDate = DateTime(currentYear, 5, 31); // May 31
+      final result = DateRangeFormatting.formatDateRange(startDate, endDate, null);
+      expect(result, 'Mar 23 - May 31');
+    });
+
+    test('returns date range format for other year (same year)', () {
+      final startDate = DateTime(2023, 8, 28); // Aug 28
+      final endDate = DateTime(2023, 9, 30); // Sep 30
+      final result = DateRangeFormatting.formatDateRange(startDate, endDate, null);
+      expect(result, 'Aug 28 - Sep 30, 2023');
+    });
+
+    test('returns date range format over multiple years', () {
+      final startDate = DateTime(2021, 4, 17); // Apr 17, 2021
+      final endDate = DateTime(2022, 4, 9); // Apr 9, 2022
+      final result = DateRangeFormatting.formatDateRange(startDate, endDate, null);
+      expect(result, 'Apr 17, 2021 - Apr 9, 2022');
+    });
+  });
+}