feat(hydrated_bloc): storagePrefix for obfuscation tolerance (#3262)

felangel · Mar 9, 2022 · b86ddf9 · b86ddf9
1 parent fa22958
commit b86ddf9
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Showing 3 changed files with 75 additions and 3 deletions.
diff --git a/packages/hydrated_bloc/lib/src/hydrated_bloc.dart b/packages/hydrated_bloc/lib/src/hydrated_bloc.dart
@@ -385,9 +385,17 @@ mixin HydratedMixin<State> on BlocBase<State> {
   /// in order to keep the caches independent of each other.
   String get id => '';
 
+  /// Storage prefix which can be overridden to provide a custom
+  /// storage namespace.
+  /// Defaults to [runtimeType] but should be overridden in cases
+  /// where stored data should be resilient to obfuscation or persist
+  /// between debug/release builds.
+  String get storagePrefix => runtimeType.toString();
+
   /// `storageToken` is used as registration token for hydrated storage.
+  /// Composed of [storagePrefix] and [id].
   @nonVirtual
-  String get storageToken => '${runtimeType.toString()}$id';
+  String get storageToken => '$storagePrefix$id';
 
   /// [clear] is used to wipe or invalidate the cache of a [HydratedBloc].
   /// Calling [clear] will delete the cached state of the bloc

diff --git a/packages/hydrated_bloc/test/hydrated_bloc_test.dart b/packages/hydrated_bloc/test/hydrated_bloc_test.dart
@@ -48,13 +48,17 @@ class MyCallbackHydratedBloc extends HydratedBloc<CounterEvent, int> {
 }
 
 class MyHydratedBloc extends HydratedBloc<int, int> {
-  MyHydratedBloc([this._id]) : super(0);
+  MyHydratedBloc([this._id, this._storagePrefix]) : super(0);
 
   final String? _id;
+  final String? _storagePrefix;
 
   @override
   String get id => _id ?? '';
 
+  @override
+  String get storagePrefix => _storagePrefix ?? super.storagePrefix;
+
   @override
   Map<String, int>? toJson(int state) {
     return {'value': state};
@@ -142,6 +146,32 @@ void main() {
       }, storage: storage);
     });
 
+    test(
+        'reads from storage once upon initialization w/custom storagePrefix/id',
+        () {
+      HydratedBlocOverrides.runZoned(() {
+        const storagePrefix = '__storagePrefix__';
+        const id = '__id__';
+        MyHydratedBloc(id, storagePrefix);
+        verify<dynamic>(() => storage.read('$storagePrefix$id')).called(1);
+      }, storage: storage);
+    });
+
+    test('writes to storage when onChange is called w/custom storagePrefix/id',
+        () {
+      HydratedBlocOverrides.runZoned(() {
+        const change = Change(
+          currentState: 0,
+          nextState: 0,
+        );
+        const expected = <String, int>{'value': 0};
+        const storagePrefix = '__storagePrefix__';
+        const id = '__id__';
+        MyHydratedBloc(id, storagePrefix).onChange(change);
+        verify(() => storage.write('$storagePrefix$id', expected)).called(2);
+      }, storage: storage);
+    });
+
     test(
         'does not read from storage on subsequent state changes '
         'when cache value exists', () async {

diff --git a/packages/hydrated_bloc/test/hydrated_cubit_test.dart b/packages/hydrated_bloc/test/hydrated_cubit_test.dart
@@ -39,14 +39,22 @@ class MyCallbackHydratedCubit extends HydratedCubit<int> {
 }
 
 class MyHydratedCubit extends HydratedCubit<int> {
-  MyHydratedCubit([this._id, this._callSuper = true]) : super(0);
+  MyHydratedCubit([
+    this._id,
+    this._callSuper = true,
+    this._storagePrefix,
+  ]) : super(0);
 
   final String? _id;
   final bool _callSuper;
+  final String? _storagePrefix;
 
   @override
   String get id => _id ?? '';
 
+  @override
+  String get storagePrefix => _storagePrefix ?? super.storagePrefix;
+
   @override
   Map<String, int> toJson(int state) => {'value': state};
 
@@ -97,6 +105,32 @@ void main() {
       }, storage: storage);
     });
 
+    test(
+        'reads from storage once upon initialization w/custom storagePrefix/id',
+        () {
+      HydratedBlocOverrides.runZoned(() {
+        const storagePrefix = '__storagePrefix__';
+        const id = '__id__';
+        MyHydratedCubit(id, true, storagePrefix);
+        verify<dynamic>(() => storage.read('$storagePrefix$id')).called(1);
+      }, storage: storage);
+    });
+
+    test('writes to storage when onChange is called w/custom storagePrefix/id',
+        () {
+      HydratedBlocOverrides.runZoned(() {
+        const change = Change(
+          currentState: 0,
+          nextState: 0,
+        );
+        const expected = <String, int>{'value': 0};
+        const storagePrefix = '__storagePrefix__';
+        const id = '__id__';
+        MyHydratedCubit(id, true, storagePrefix).onChange(change);
+        verify(() => storage.write('$storagePrefix$id', expected)).called(2);
+      }, storage: storage);
+    });
+
     test(
         'does not read from storage on subsequent state changes '
         'when cache value exists', () {