Source Code added

mobile/test/modules/extensions/asset_extensions_test.dart

@@ -0,0 +1,113 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:immich_mobile/domain/models/exif.model.dart';
+import 'package:immich_mobile/entities/asset.entity.dart';
+import 'package:immich_mobile/extensions/asset_extensions.dart';
+import 'package:timezone/data/latest.dart';
+import 'package:timezone/timezone.dart';
+
+ExifInfo makeExif({DateTime? dateTimeOriginal, String? timeZone}) {
+  return ExifInfo(dateTimeOriginal: dateTimeOriginal, timeZone: timeZone);
+}
+
+Asset makeAsset({required String id, required DateTime createdAt, ExifInfo? exifInfo}) {
+  return Asset(
+    checksum: '',
+    localId: id,
+    remoteId: id,
+    ownerId: 1,
+    fileCreatedAt: createdAt,
+    fileModifiedAt: DateTime.now(),
+    updatedAt: DateTime.now(),
+    durationInSeconds: 0,
+    type: AssetType.image,
+    fileName: id,
+    isFavorite: false,
+    isArchived: false,
+    isTrashed: false,
+    exifInfo: exifInfo,
+  );
+}
+
+void main() {
+  // Init Timezone DB
+  initializeTimeZones();
+
+  group("Returns local time and offset if no exifInfo", () {
+    test('returns createdAt directly if in local', () {
+      final createdAt = DateTime(2023, 12, 12, 12, 12, 12);
+      final a = makeAsset(id: '1', createdAt: createdAt);
+      final (dt, tz) = a.getTZAdjustedTimeAndOffset();
+
+      expect(createdAt, dt);
+      expect(createdAt.timeZoneOffset, tz);
+    });
+
+    test('returns createdAt in local if in utc', () {
+      final createdAt = DateTime.utc(2023, 12, 12, 12, 12, 12);
+      final a = makeAsset(id: '1', createdAt: createdAt);
+      final (dt, tz) = a.getTZAdjustedTimeAndOffset();
+
+      final localCreatedAt = createdAt.toLocal();
+      expect(localCreatedAt, dt);
+      expect(localCreatedAt.timeZoneOffset, tz);
+    });
+  });
+
+  group("Returns dateTimeOriginal", () {
+    test('Returns dateTimeOriginal in UTC from exifInfo without timezone', () {
+      final createdAt = DateTime.parse("2023-01-27T14:00:00-0500");
+      final dateTimeOriginal = DateTime.parse("2022-01-27T14:00:00+0530");
+      final e = makeExif(dateTimeOriginal: dateTimeOriginal);
+      final a = makeAsset(id: '1', createdAt: createdAt, exifInfo: e);
+      final (dt, tz) = a.getTZAdjustedTimeAndOffset();
+
+      final dateTimeInUTC = dateTimeOriginal.toUtc();
+      expect(dateTimeInUTC, dt);
+      expect(dateTimeInUTC.timeZoneOffset, tz);
+    });
+
+    test('Returns dateTimeOriginal in UTC from exifInfo with invalid timezone', () {
+      final createdAt = DateTime.parse("2023-01-27T14:00:00-0500");
+      final dateTimeOriginal = DateTime.parse("2022-01-27T14:00:00+0530");
+      final e = makeExif(dateTimeOriginal: dateTimeOriginal, timeZone: "#_#"); // Invalid timezone
+      final a = makeAsset(id: '1', createdAt: createdAt, exifInfo: e);
+      final (dt, tz) = a.getTZAdjustedTimeAndOffset();
+
+      final dateTimeInUTC = dateTimeOriginal.toUtc();
+      expect(dateTimeInUTC, dt);
+      expect(dateTimeInUTC.timeZoneOffset, tz);
+    });
+  });
+
+  group("Returns adjusted time if timezone available", () {
+    test('With timezone as location', () {
+      final createdAt = DateTime.parse("2023-01-27T14:00:00-0500");
+      final dateTimeOriginal = DateTime.parse("2022-01-27T14:00:00+0530");
+      const location = "Asia/Hong_Kong";
+      final e = makeExif(dateTimeOriginal: dateTimeOriginal, timeZone: location);
+      final a = makeAsset(id: '1', createdAt: createdAt, exifInfo: e);
+      final (dt, tz) = a.getTZAdjustedTimeAndOffset();
+
+      final adjustedTime = TZDateTime.from(dateTimeOriginal.toUtc(), getLocation(location));
+      expect(adjustedTime, dt);
+      expect(adjustedTime.timeZoneOffset, tz);
+    });
+
+    test('With timezone as offset', () {
+      final createdAt = DateTime.parse("2023-01-27T14:00:00-0500");
+      final dateTimeOriginal = DateTime.parse("2022-01-27T14:00:00+0530");
+      const offset = "utc+08:00";
+      final e = makeExif(dateTimeOriginal: dateTimeOriginal, timeZone: offset);
+      final a = makeAsset(id: '1', createdAt: createdAt, exifInfo: e);
+      final (dt, tz) = a.getTZAdjustedTimeAndOffset();
+
+      final location = getLocation("Asia/Hong_Kong");
+      final offsetFromLocation = Duration(milliseconds: location.currentTimeZone.offset);
+      final adjustedTime = dateTimeOriginal.toUtc().add(offsetFromLocation);
+
+      // Adds the offset to the actual time and returns the offset separately
+      expect(adjustedTime, dt);
+      expect(offsetFromLocation, tz);
+    });
+  });
+}