test: add unit tests for platform interface

flutter_secure_storage/test/flutter_secure_storage_mock.dart

@@ -0,0 +1,56 @@
+import 'package:flutter_secure_storage_platform_interface/flutter_secure_storage_platform_interface.dart';
+import 'package:mocktail/mocktail.dart';
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+
+class MockFlutterSecureStoragePlatform extends Mock
+    with MockPlatformInterfaceMixin
+    implements FlutterSecureStoragePlatform {}
+
+class ImplementsFlutterSecureStoragePlatform extends Mock
+    implements FlutterSecureStoragePlatform {}
+
+class ExtendsFlutterSecureStoragePlatform extends FlutterSecureStoragePlatform {
+  @override
+  Future<bool> containsKey({
+    required String key,
+    required Map<String, String> options,
+  }) =>
+      Future.value(true);
+
+  @override
+  Future<void> delete({
+    required String key,
+    required Map<String, String> options,
+  }) =>
+      Future<void>.value();
+
+  @override
+  Future<void> deleteAll({required Map<String, String> options}) =>
+      Future<void>.value();
+
+  @override
+  Future<String?> read({
+    required String key,
+    required Map<String, String> options,
+  }) =>
+      Future<String?>.value();
+
+  @override
+  Future<Map<String, String>> readAll({required Map<String, String> options}) =>
+      Future.value(<String, String>{});
+
+  @override
+  Future<void> write({
+    required String key,
+    required String value,
+    required Map<String, String> options,
+  }) =>
+      Future<void>.value();
+
+  // @override
+  // Future<bool> isCupertinoProtectedDataAvailable() => Future.value(true);
+  //
+  // @override
+  // Stream<bool> get onCupertinoProtectedDataAvailabilityChanged =>
+  //     Stream.value(true);
+}

flutter_secure_storage/test/flutter_secure_storage_test.dart

@@ -1,25 +1,169 @@
+import 'package:flutter/services.dart';
 import 'package:flutter_secure_storage/flutter_secure_storage.dart';
 import 'package:flutter_secure_storage_platform_interface/flutter_secure_storage_platform_interface.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mocktail/mocktail.dart';
-import 'package:plugin_platform_interface/plugin_platform_interface.dart';
 
-// ✅ Correct Mock Class Implementation
-class MockFlutterSecureStoragePlatform extends Mock
-    with MockPlatformInterfaceMixin
-    implements FlutterSecureStoragePlatform {}
+import 'flutter_secure_storage_mock.dart';
 
 void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
   late FlutterSecureStorage storage;
   late MockFlutterSecureStoragePlatform mockPlatform;
 
+  const channel = MethodChannel('plugins.it_nomads.com/flutter_secure_storage');
+  final methodStorage = MethodChannelFlutterSecureStorage();
+  final log = <MethodCall>[];
+
+  Future<bool?>? handler(MethodCall methodCall) async {
+    log.add(methodCall);
+    if (methodCall.method == 'containsKey') {
+      return true;
+    } else if (methodCall.method == 'isProtectedDataAvailable') {
+      return true;
+    }
+    return null;
+  }
+
   setUp(() {
     mockPlatform = MockFlutterSecureStoragePlatform();
     FlutterSecureStoragePlatform.instance = mockPlatform;
     storage = const FlutterSecureStorage();
+
+    // Ensure method channel mock is set up for the tests
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(channel, handler);
+
+    log.clear(); // Clear logs before each test
+  });
+
+  tearDown(() {
+    log.clear(); // Clear logs after each test
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(channel, null); // Remove the mock handler
+  });
+
+  group('Method Channel Interaction Tests for FlutterSecureStorage', () {
+    test('read', () async {
+      const key = 'test_key';
+      const options = <String, String>{};
+      await methodStorage.read(key: key, options: options);
+
+      expect(
+        log,
+        <Matcher>[
+          isMethodCall(
+            'read',
+            arguments: <String, Object>{
+              'key': key,
+              'options': options,
+            },
+          ),
+        ],
+      );
+    });
+
+    test('write', () async {
+      const key = 'test_key';
+      const options = <String, String>{};
+      await methodStorage.write(key: key, value: 'test', options: options);
+
+      expect(
+        log,
+        <Matcher>[
+          isMethodCall(
+            'write',
+            arguments: <String, Object>{
+              'key': key,
+              'value': 'test',
+              'options': options,
+            },
+          ),
+        ],
+      );
+    });
+
+    test('containsKey', () async {
+      const key = 'test_key';
+      const options = <String, String>{};
+      await methodStorage.write(key: key, value: 'test', options: options);
+
+      final result =
+          await methodStorage.containsKey(key: key, options: options);
+
+      expect(result, true);
+    });
+
+    test('delete', () async {
+      const key = 'test_key';
+      const options = <String, String>{};
+      await methodStorage.write(key: key, value: 'test', options: options);
+      await methodStorage.delete(key: key, options: options);
+
+      expect(
+        log,
+        <Matcher>[
+          isMethodCall(
+            'write',
+            arguments: <String, Object>{
+              'key': key,
+              'value': 'test',
+              'options': options,
+            },
+          ),
+          isMethodCall(
+            'delete',
+            arguments: <String, Object>{
+              'key': key,
+              'options': options,
+            },
+          ),
+        ],
+      );
+    });
+
+    test('deleteAll', () async {
+      const options = <String, String>{};
+      await methodStorage.deleteAll(options: options);
+
+      expect(
+        log,
+        <Matcher>[
+          isMethodCall(
+            'deleteAll',
+            arguments: <String, Object>{
+              'options': options,
+            },
+          ),
+        ],
+      );
+    });
+  });
+
+  group('Platform-Specific Interface Tests', () {
+    test('Cannot be implemented with `implements`', () {
+      expect(
+        () {
+          FlutterSecureStoragePlatform.instance =
+              ImplementsFlutterSecureStoragePlatform();
+        },
+        throwsA(isInstanceOf<AssertionError>()),
+      );
+    });
+
+    test('Can be mocked with `implements`', () {
+      final mock = MockFlutterSecureStoragePlatform();
+      FlutterSecureStoragePlatform.instance = mock;
+    });
+
+    test('Can be extended', () {
+      FlutterSecureStoragePlatform.instance =
+          ExtendsFlutterSecureStoragePlatform();
+    });
   });
 
-  group('FlutterSecureStorage Tests', () {
+  group('FlutterSecureStorage Methods Invocation Tests', () {
     const testKey = 'testKey';
     const testValue = 'testValue';
 
@@ -118,7 +262,7 @@ void main() {
     });
   });
 
-  group('AndroidOptions Tests', () {
+  group('AndroidOptions Configuration Tests', () {
     test('Default AndroidOptions should have correct default values', () {
       const options = AndroidOptions.defaultOptions;
 
@@ -201,7 +345,7 @@ void main() {
     });
   });
 
-  group('WebOptions Tests', () {
+  group('WebOptions Configuration Tests', () {
     test('Default WebOptions should have correct default values', () {
       const options = WebOptions.defaultOptions;
 
@@ -261,7 +405,7 @@ void main() {
     });
   });
 
-  group('WindowsOptions Tests', () {
+  group('WindowsOptions Configuration Tests', () {
     test('Default WindowsOptions should have correct default values', () {
       const options = WindowsOptions.defaultOptions;
 
@@ -308,7 +452,7 @@ void main() {
     });
   });
 
-  group('IOSOptions Tests', () {
+  group('iOSOptions Configuration Tests', () {
     test('Default IOSOptions should have correct default values', () {
       const options = IOSOptions.defaultOptions;
 
@@ -368,8 +512,8 @@ void main() {
     });
   });
 
-  group('MacOsOptions Tests', () {
-    test('Default MacOsOptions should have correct default values', () {
+  group('macOSOptions Configuration Tests', () {
+    test('Default macOSOptions should have correct default values', () {
       // Ignore for test
       // ignore: use_named_constants
       const options = MacOsOptions();
@@ -382,7 +526,7 @@ void main() {
       });
     });
 
-    test('MacOsOptions with custom values', () {
+    test('macOSOptions with custom values', () {
       const options = MacOsOptions(
         accountName: 'macAccount',
         groupId: 'group.mac.example',
@@ -400,7 +544,7 @@ void main() {
       });
     });
 
-    test('MacOsOptions defaultOptions matches default constructor', () {
+    test('macOSOptions defaultOptions matches default constructor', () {
       const defaultOptions = MacOsOptions.defaultOptions;
       // Ignore for test
       // ignore: use_named_constants