diff --git a/lib/data/shared_prefs_service.dart b/lib/data/shared_prefs_service.dart
index a86a7d1..56207ea 100644
--- a/lib/data/shared_prefs_service.dart
+++ b/lib/data/shared_prefs_service.dart
@@ -10,22 +10,22 @@ import 'package:m3_lightmeter_resources/m3_lightmeter_resources.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
 class UserPreferencesService {
-  static const _isoKey = "iso";
-  static const _ndFilterKey = "ndFilter";
+  static const isoKey = "iso";
+  static const ndFilterKey = "ndFilter";
 
-  static const _evSourceTypeKey = "evSourceType";
-  static const _cameraEvCalibrationKey = "cameraEvCalibration";
-  static const _lightSensorEvCalibrationKey = "lightSensorEvCalibration";
-  static const _meteringScreenLayoutKey = "meteringScreenLayout";
-  static const _filmKey = "film";
+  static const evSourceTypeKey = "evSourceType";
+  static const cameraEvCalibrationKey = "cameraEvCalibration";
+  static const lightSensorEvCalibrationKey = "lightSensorEvCalibration";
+  static const meteringScreenLayoutKey = "meteringScreenLayout";
+  static const filmKey = "film";
 
-  static const _caffeineKey = "caffeine";
-  static const _hapticsKey = "haptics";
-  static const _localeKey = "locale";
+  static const caffeineKey = "caffeine";
+  static const hapticsKey = "haptics";
+  static const localeKey = "locale";
 
-  static const _themeTypeKey = "themeType";
-  static const _primaryColorKey = "primaryColor";
-  static const _dynamicColorKey = "dynamicColor";
+  static const themeTypeKey = "themeType";
+  static const primaryColorKey = "primaryColor";
+  static const dynamicColorKey = "dynamicColor";
 
   final SharedPreferences _sharedPreferences;
 
@@ -69,22 +69,22 @@ class UserPreferencesService {
   }
 
   IsoValue get iso =>
-      IsoValue.values.firstWhere((v) => v.value == (_sharedPreferences.getInt(_isoKey) ?? 100));
-  set iso(IsoValue value) => _sharedPreferences.setInt(_isoKey, value.value);
+      IsoValue.values.firstWhere((v) => v.value == (_sharedPreferences.getInt(isoKey) ?? 100));
+  set iso(IsoValue value) => _sharedPreferences.setInt(isoKey, value.value);
 
   NdValue get ndFilter =>
-      NdValue.values.firstWhere((v) => v.value == (_sharedPreferences.getInt(_ndFilterKey) ?? 0));
-  set ndFilter(NdValue value) => _sharedPreferences.setInt(_ndFilterKey, value.value);
+      NdValue.values.firstWhere((v) => v.value == (_sharedPreferences.getInt(ndFilterKey) ?? 0));
+  set ndFilter(NdValue value) => _sharedPreferences.setInt(ndFilterKey, value.value);
 
   EvSourceType get evSourceType =>
-      EvSourceType.values[_sharedPreferences.getInt(_evSourceTypeKey) ?? 0];
-  set evSourceType(EvSourceType value) => _sharedPreferences.setInt(_evSourceTypeKey, value.index);
+      EvSourceType.values[_sharedPreferences.getInt(evSourceTypeKey) ?? 0];
+  set evSourceType(EvSourceType value) => _sharedPreferences.setInt(evSourceTypeKey, value.index);
 
-  bool get caffeine => _sharedPreferences.getBool(_caffeineKey) ?? false;
-  set caffeine(bool value) => _sharedPreferences.setBool(_caffeineKey, value);
+  bool get caffeine => _sharedPreferences.getBool(caffeineKey) ?? false;
+  set caffeine(bool value) => _sharedPreferences.setBool(caffeineKey, value);
 
   MeteringScreenLayoutConfig get meteringScreenLayout {
-    final configJson = _sharedPreferences.getString(_meteringScreenLayoutKey);
+    final configJson = _sharedPreferences.getString(meteringScreenLayoutKey);
     if (configJson != null) {
       return MeteringScreenLayoutConfigJson.fromJson(
         json.decode(configJson) as Map<String, dynamic>,
@@ -98,40 +98,40 @@ class UserPreferencesService {
   }
 
   set meteringScreenLayout(MeteringScreenLayoutConfig value) =>
-      _sharedPreferences.setString(_meteringScreenLayoutKey, json.encode(value.toJson()));
+      _sharedPreferences.setString(meteringScreenLayoutKey, json.encode(value.toJson()));
 
-  bool get haptics => _sharedPreferences.getBool(_hapticsKey) ?? true;
-  set haptics(bool value) => _sharedPreferences.setBool(_hapticsKey, value);
+  bool get haptics => _sharedPreferences.getBool(hapticsKey) ?? true;
+  set haptics(bool value) => _sharedPreferences.setBool(hapticsKey, value);
 
   SupportedLocale get locale => SupportedLocale.values.firstWhere(
-        (e) => e.toString() == _sharedPreferences.getString(_localeKey),
+        (e) => e.toString() == _sharedPreferences.getString(localeKey),
         orElse: () => SupportedLocale.en,
       );
-  set locale(SupportedLocale value) => _sharedPreferences.setString(_localeKey, value.toString());
+  set locale(SupportedLocale value) => _sharedPreferences.setString(localeKey, value.toString());
 
-  double get cameraEvCalibration => _sharedPreferences.getDouble(_cameraEvCalibrationKey) ?? 0.0;
+  double get cameraEvCalibration => _sharedPreferences.getDouble(cameraEvCalibrationKey) ?? 0.0;
   set cameraEvCalibration(double value) =>
-      _sharedPreferences.setDouble(_cameraEvCalibrationKey, value);
+      _sharedPreferences.setDouble(cameraEvCalibrationKey, value);
 
   double get lightSensorEvCalibration =>
-      _sharedPreferences.getDouble(_lightSensorEvCalibrationKey) ?? 0.0;
+      _sharedPreferences.getDouble(lightSensorEvCalibrationKey) ?? 0.0;
   set lightSensorEvCalibration(double value) =>
-      _sharedPreferences.setDouble(_lightSensorEvCalibrationKey, value);
+      _sharedPreferences.setDouble(lightSensorEvCalibrationKey, value);
 
-  ThemeType get themeType => ThemeType.values[_sharedPreferences.getInt(_themeTypeKey) ?? 0];
-  set themeType(ThemeType value) => _sharedPreferences.setInt(_themeTypeKey, value.index);
+  ThemeType get themeType => ThemeType.values[_sharedPreferences.getInt(themeTypeKey) ?? 0];
+  set themeType(ThemeType value) => _sharedPreferences.setInt(themeTypeKey, value.index);
 
-  Color get primaryColor => Color(_sharedPreferences.getInt(_primaryColorKey) ?? 0xff2196f3);
-  set primaryColor(Color value) => _sharedPreferences.setInt(_primaryColorKey, value.value);
+  Color get primaryColor => Color(_sharedPreferences.getInt(primaryColorKey) ?? 0xff2196f3);
+  set primaryColor(Color value) => _sharedPreferences.setInt(primaryColorKey, value.value);
 
-  bool get dynamicColor => _sharedPreferences.getBool(_dynamicColorKey) ?? false;
-  set dynamicColor(bool value) => _sharedPreferences.setBool(_dynamicColorKey, value);
+  bool get dynamicColor => _sharedPreferences.getBool(dynamicColorKey) ?? false;
+  set dynamicColor(bool value) => _sharedPreferences.setBool(dynamicColorKey, value);
 
   Film get film => Film.values.firstWhere(
-        (e) => e.name == _sharedPreferences.getString(_filmKey),
+        (e) => e.name == _sharedPreferences.getString(filmKey),
         orElse: () => Film.values.first,
       );
-  set film(Film value) => _sharedPreferences.setString(_filmKey, value.name);
+  set film(Film value) => _sharedPreferences.setString(filmKey, value.name);
 
   String get selectedEquipmentProfileId => '';
   set selectedEquipmentProfileId(String id) {}
diff --git a/test/data/shared_prefs_service_test.dart b/test/data/shared_prefs_service_test.dart
new file mode 100644
index 0000000..e2b1088
--- /dev/null
+++ b/test/data/shared_prefs_service_test.dart
@@ -0,0 +1,326 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lightmeter/data/models/ev_source_type.dart';
+import 'package:lightmeter/data/models/film.dart';
+import 'package:lightmeter/data/models/metering_screen_layout_config.dart';
+import 'package:lightmeter/data/models/supported_locale.dart';
+import 'package:lightmeter/data/models/theme_type.dart';
+import 'package:lightmeter/data/shared_prefs_service.dart';
+import 'package:lightmeter/providers/theme_provider.dart';
+import 'package:m3_lightmeter_resources/m3_lightmeter_resources.dart';
+import 'package:mocktail/mocktail.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class _MockSharedPreferences extends Mock implements SharedPreferences {}
+
+void main() {
+  late _MockSharedPreferences sharedPreferences;
+  late UserPreferencesService service;
+
+  setUpAll(() {
+    sharedPreferences = _MockSharedPreferences();
+    service = UserPreferencesService(sharedPreferences);
+  });
+
+  group('iso', () {
+    test('get default', () {
+      when(() => sharedPreferences.getInt(UserPreferencesService.isoKey)).thenReturn(null);
+      expect(service.iso, const IsoValue(100, StopType.full));
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getInt(UserPreferencesService.isoKey)).thenReturn(100);
+      expect(service.iso, const IsoValue(100, StopType.full));
+    });
+
+    test('set', () {
+      when(() => sharedPreferences.setInt(UserPreferencesService.isoKey, 200))
+          .thenAnswer((_) => Future.value(true));
+      service.iso = const IsoValue(200, StopType.full);
+      verify(() => sharedPreferences.setInt(UserPreferencesService.isoKey, 200)).called(1);
+    });
+  });
+
+  group('ndFilter', () {
+    test('get default', () {
+      when(() => sharedPreferences.getInt(UserPreferencesService.ndFilterKey)).thenReturn(null);
+      expect(service.ndFilter, const NdValue(0));
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getInt(UserPreferencesService.ndFilterKey)).thenReturn(4);
+      expect(service.ndFilter, const NdValue(4));
+    });
+
+    test('set', () {
+      when(() => sharedPreferences.setInt(UserPreferencesService.ndFilterKey, 0))
+          .thenAnswer((_) => Future.value(true));
+      service.ndFilter = const NdValue(0);
+      verify(() => sharedPreferences.setInt(UserPreferencesService.ndFilterKey, 0)).called(1);
+    });
+  });
+
+  group('evSourceType', () {
+    test('get default', () {
+      when(() => sharedPreferences.getInt(UserPreferencesService.evSourceTypeKey)).thenReturn(null);
+      expect(service.evSourceType, EvSourceType.camera);
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getInt(UserPreferencesService.evSourceTypeKey)).thenReturn(1);
+      expect(service.evSourceType, EvSourceType.sensor);
+    });
+
+    test('set', () {
+      when(() => sharedPreferences.setInt(UserPreferencesService.evSourceTypeKey, 1))
+          .thenAnswer((_) => Future.value(true));
+      service.evSourceType = EvSourceType.sensor;
+      verify(() => sharedPreferences.setInt(UserPreferencesService.evSourceTypeKey, 1)).called(1);
+    });
+  });
+
+  group('caffeine', () {
+    test('get default', () {
+      when(() => sharedPreferences.getBool(UserPreferencesService.caffeineKey)).thenReturn(null);
+      expect(service.caffeine, false);
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getBool(UserPreferencesService.caffeineKey)).thenReturn(true);
+      expect(service.caffeine, true);
+    });
+
+    test('set', () {
+      when(() => sharedPreferences.setBool(UserPreferencesService.caffeineKey, false))
+          .thenAnswer((_) => Future.value(true));
+      service.caffeine = false;
+      verify(() => sharedPreferences.setBool(UserPreferencesService.caffeineKey, false)).called(1);
+    });
+  });
+
+  group('meteringScreenLayout', () {
+    test('get default', () {
+      when(
+        () => sharedPreferences.getString(UserPreferencesService.meteringScreenLayoutKey),
+      ).thenReturn(null);
+      expect(
+        service.meteringScreenLayout,
+        {
+          MeteringScreenLayoutFeature.extremeExposurePairs: true,
+          MeteringScreenLayoutFeature.filmPicker: true,
+        },
+      );
+    });
+
+    test('get', () {
+      when(
+        () => sharedPreferences.getString(UserPreferencesService.meteringScreenLayoutKey),
+      ).thenReturn("""{"0":false,"1":true}""");
+      expect(
+        service.meteringScreenLayout,
+        {
+          MeteringScreenLayoutFeature.extremeExposurePairs: false,
+          MeteringScreenLayoutFeature.filmPicker: true,
+        },
+      );
+    });
+
+    test('set', () {
+      when(
+        () => sharedPreferences.setString(
+          UserPreferencesService.meteringScreenLayoutKey,
+          """{"0":false,"1":true}""",
+        ),
+      ).thenAnswer((_) => Future.value(true));
+      service.meteringScreenLayout = {
+        MeteringScreenLayoutFeature.extremeExposurePairs: false,
+        MeteringScreenLayoutFeature.filmPicker: true,
+      };
+      verify(
+        () => sharedPreferences.setString(
+          UserPreferencesService.meteringScreenLayoutKey,
+          """{"0":false,"1":true}""",
+        ),
+      ).called(1);
+    });
+  });
+
+  group('haptics', () {
+    test('get default', () {
+      when(() => sharedPreferences.getBool(UserPreferencesService.hapticsKey)).thenReturn(null);
+      expect(service.haptics, true);
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getBool(UserPreferencesService.hapticsKey)).thenReturn(true);
+      expect(service.haptics, true);
+    });
+
+    test('set', () {
+      when(() => sharedPreferences.setBool(UserPreferencesService.hapticsKey, false))
+          .thenAnswer((_) => Future.value(true));
+      service.haptics = false;
+      verify(() => sharedPreferences.setBool(UserPreferencesService.hapticsKey, false)).called(1);
+    });
+  });
+
+  group('locale', () {
+    test('get default', () {
+      when(() => sharedPreferences.getString(UserPreferencesService.localeKey)).thenReturn(null);
+      expect(service.locale, SupportedLocale.en);
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getString(UserPreferencesService.localeKey))
+          .thenReturn('SupportedLocale.ru');
+      expect(service.locale, SupportedLocale.ru);
+    });
+
+    test('set', () {
+      when(
+        () => sharedPreferences.setString(UserPreferencesService.localeKey, 'SupportedLocale.en'),
+      ).thenAnswer((_) => Future.value(true));
+      service.locale = SupportedLocale.en;
+      verify(
+        () => sharedPreferences.setString(UserPreferencesService.localeKey, 'SupportedLocale.en'),
+      ).called(1);
+    });
+  });
+
+  group('cameraEvCalibration', () {
+    test('get default', () {
+      when(() => sharedPreferences.getDouble(UserPreferencesService.cameraEvCalibrationKey))
+          .thenReturn(null);
+      expect(service.cameraEvCalibration, 0.0);
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getDouble(UserPreferencesService.cameraEvCalibrationKey))
+          .thenReturn(2.0);
+      expect(service.cameraEvCalibration, 2.0);
+    });
+
+    test('set', () {
+      when(
+        () => sharedPreferences.setDouble(UserPreferencesService.cameraEvCalibrationKey, 1.0),
+      ).thenAnswer((_) => Future.value(true));
+      service.cameraEvCalibration = 1.0;
+      verify(
+        () => sharedPreferences.setDouble(UserPreferencesService.cameraEvCalibrationKey, 1.0),
+      ).called(1);
+    });
+  });
+
+  group('lightSensorEvCalibration', () {
+    test('get default', () {
+      when(() => sharedPreferences.getDouble(UserPreferencesService.lightSensorEvCalibrationKey))
+          .thenReturn(null);
+      expect(service.lightSensorEvCalibration, 0.0);
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getDouble(UserPreferencesService.lightSensorEvCalibrationKey))
+          .thenReturn(2.0);
+      expect(service.lightSensorEvCalibration, 2.0);
+    });
+
+    test('set', () {
+      when(
+        () => sharedPreferences.setDouble(UserPreferencesService.lightSensorEvCalibrationKey, 1.0),
+      ).thenAnswer((_) => Future.value(true));
+      service.lightSensorEvCalibration = 1.0;
+      verify(
+        () => sharedPreferences.setDouble(UserPreferencesService.lightSensorEvCalibrationKey, 1.0),
+      ).called(1);
+    });
+  });
+
+  group('themeType', () {
+    test('get default', () {
+      when(() => sharedPreferences.getInt(UserPreferencesService.themeTypeKey)).thenReturn(null);
+      expect(service.themeType, ThemeType.light);
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getInt(UserPreferencesService.themeTypeKey)).thenReturn(1);
+      expect(service.themeType, ThemeType.dark);
+    });
+
+    test('set', () {
+      when(
+        () => sharedPreferences.setInt(UserPreferencesService.themeTypeKey, 1),
+      ).thenAnswer((_) => Future.value(true));
+      service.themeType = ThemeType.dark;
+      verify(
+        () => sharedPreferences.setInt(UserPreferencesService.themeTypeKey, 1),
+      ).called(1);
+    });
+  });
+
+  group('primaryColor', () {
+    test('get default', () {
+      when(() => sharedPreferences.getInt(UserPreferencesService.primaryColorKey)).thenReturn(null);
+      expect(service.primaryColor, ThemeProvider.primaryColorsList[5]);
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getInt(UserPreferencesService.primaryColorKey))
+          .thenReturn(0xff9c27b0);
+      expect(service.primaryColor, ThemeProvider.primaryColorsList[2]);
+    });
+
+    test('set', () {
+      when(
+        () => sharedPreferences.setInt(UserPreferencesService.primaryColorKey, 0xff000000),
+      ).thenAnswer((_) => Future.value(true));
+      service.primaryColor = Colors.black;
+      verify(
+        () => sharedPreferences.setInt(UserPreferencesService.primaryColorKey, 0xff000000),
+      ).called(1);
+    });
+  });
+
+  group('dynamicColor', () {
+    test('get default', () {
+      when(() => sharedPreferences.getBool(UserPreferencesService.dynamicColorKey))
+          .thenReturn(null);
+      expect(service.dynamicColor, false);
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getBool(UserPreferencesService.dynamicColorKey))
+          .thenReturn(true);
+      expect(service.dynamicColor, true);
+    });
+
+    test('set', () {
+      when(() => sharedPreferences.setBool(UserPreferencesService.dynamicColorKey, false))
+          .thenAnswer((_) => Future.value(true));
+      service.dynamicColor = false;
+      verify(() => sharedPreferences.setBool(UserPreferencesService.dynamicColorKey, false))
+          .called(1);
+    });
+  });
+
+  group('film', () {
+    test('get default', () {
+      when(() => sharedPreferences.getString(UserPreferencesService.filmKey)).thenReturn(null);
+      expect(service.film, Film.values.first);
+    });
+
+    test('get', () {
+      when(() => sharedPreferences.getString(UserPreferencesService.filmKey))
+          .thenReturn('Fomapan ACTION 400');
+      expect(service.film, const FomapanFilm.action400());
+    });
+
+    test('set', () {
+      when(() => sharedPreferences.setString(UserPreferencesService.filmKey, 'Fomapan ACTION 400'))
+          .thenAnswer((_) => Future.value(true));
+      service.film = const FomapanFilm.action400();
+      verify(
+        () => sharedPreferences.setString(UserPreferencesService.filmKey, 'Fomapan ACTION 400'),
+      ).called(1);
+    });
+  });
+}