diff --git a/test/features/public_asset/domain/usecase/clean_up_public_assets_interactor_test.dart b/test/features/public_asset/domain/usecase/clean_up_public_assets_interactor_test.dart
new file mode 100644
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+++ b/test/features/public_asset/domain/usecase/clean_up_public_assets_interactor_test.dart
@@ -0,0 +1,461 @@
+import 'package:dartz/dartz.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:jmap_dart_client/jmap/account_id.dart';
+import 'package:jmap_dart_client/jmap/core/id.dart';
+import 'package:jmap_dart_client/jmap/core/session/session.dart';
+import 'package:jmap_dart_client/jmap/identities/identity.dart';
+import 'package:mockito/annotations.dart';
+import 'package:mockito/mockito.dart';
+import 'package:tmail_ui_user/features/manage_account/presentation/model/identity_action_type.dart';
+import 'package:tmail_ui_user/features/public_asset/domain/model/public_assets_in_identity_arguments.dart';
+import 'package:tmail_ui_user/features/public_asset/domain/state/add_identity_to_public_assets_state.dart';
+import 'package:tmail_ui_user/features/public_asset/domain/state/delete_public_assets_state.dart';
+import 'package:tmail_ui_user/features/public_asset/domain/state/remove_identity_from_public_assets_state.dart';
+import 'package:tmail_ui_user/features/public_asset/domain/usecase/add_identity_to_public_assets_interactor.dart';
+import 'package:tmail_ui_user/features/public_asset/domain/usecase/clean_up_public_assets_interactor.dart';
+import 'package:tmail_ui_user/features/public_asset/domain/usecase/delete_public_assets_interactor.dart';
+import 'package:tmail_ui_user/features/public_asset/domain/usecase/remove_identity_from_public_assets_interactor.dart';
+
+import 'clean_up_public_assets_interactor_test.mocks.dart';
+
+@GenerateNiceMocks([
+  MockSpec<RemoveIdentityFromPublicAssetsInteractor>(),
+  MockSpec<DeletePublicAssetsInteractor>(),
+  MockSpec<AddIdentityToPublicAssetsInteractor>(),
+  MockSpec<Session>(),
+  MockSpec<AccountId>(),
+])
+void main() {
+  final removeIdentityFromPublicAssetsInteractor = MockRemoveIdentityFromPublicAssetsInteractor();
+  final deletePublicAssetsInteractor = MockDeletePublicAssetsInteractor();
+  final addIdentityToPublicAssetsInteractor = MockAddIdentityToPublicAssetsInteractor();
+  final cleanUpPublicAssetsInteractor = CleanUpPublicAssetsInteractor(
+    removeIdentityFromPublicAssetsInteractor,
+    deletePublicAssetsInteractor,
+    addIdentityToPublicAssetsInteractor,
+  );
+
+  group('clean up public assets interactor test:', () {
+    final session = MockSession();
+    final accountId = MockAccountId();
+
+    test(
+      'should destroy unused public assets '
+      'when there are picked public assets that are deleted',
+    () async {
+      // arrange
+      final identityId = IdentityId(Id('id-1'));
+      const identityActionType = IdentityActionType.edit;
+      final toBeUsedPublicAssetId = Id('public-asset-1');
+      final toBeDeletedPublicAssetId = Id('public-asset-2');
+      final newlyPickedPublicAssetIds = [toBeUsedPublicAssetId, toBeDeletedPublicAssetId];
+      final htmlSignature = '<img src="public-asset-1" public-asset-id="${toBeUsedPublicAssetId.value}"/>';
+      final publicAssetsInIdentityArguments = PublicAssetsInIdentityArguments(
+        htmlSignature: htmlSignature,
+        preExistingPublicAssetIds: [],
+        newlyPickedPublicAssetIds: newlyPickedPublicAssetIds);
+
+      when(deletePublicAssetsInteractor
+        .execute(any, any, publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(DeletePublicAssetsSuccessState())));
+      when(removeIdentityFromPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(RemoveIdentityFromPublicAssetsSuccessState())));
+      when(addIdentityToPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(AddIdentityToPublicAssetsSuccessState())));
+  
+      // act
+      await cleanUpPublicAssetsInteractor.execute(
+        session,
+        accountId,
+        identityId: identityId,
+        identityActionType: identityActionType,
+        publicAssetsInIdentityArguments: publicAssetsInIdentityArguments).last;
+      
+      // assert
+      verify(
+        deletePublicAssetsInteractor.execute(
+          session,
+          accountId,
+          publicAssetIds: [toBeDeletedPublicAssetId])
+      ).called(1);
+      verifyNever(
+        removeIdentityFromPublicAssetsInteractor.execute(
+          any,
+          any,
+          identityId: anyNamed('identityId'),
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+      verifyNever(
+        addIdentityToPublicAssetsInteractor.execute(
+          any,
+          any,
+          identityId: anyNamed('identityId'),
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+    });
+
+    test(
+      'should remove reference of unused public assets '
+      'when there are existing public assets that are deleted',
+    () async {
+      // arrange
+      final identityId = IdentityId(Id('id-1'));
+      const identityActionType = IdentityActionType.edit;
+      final toBeUsedPublicAssetId = Id('public-asset-1');
+      final toBeDeletedPublicAssetId = Id('public-asset-2');
+      final preExistingPublicAssetIds = [toBeUsedPublicAssetId, toBeDeletedPublicAssetId];
+      final htmlSignature = '<img src="public-asset-1" public-asset-id="${toBeUsedPublicAssetId.value}"/>';
+      final publicAssetsInIdentityArguments = PublicAssetsInIdentityArguments(
+        htmlSignature: htmlSignature,
+        preExistingPublicAssetIds: preExistingPublicAssetIds,
+        newlyPickedPublicAssetIds: []);
+
+      when(deletePublicAssetsInteractor
+        .execute(any, any, publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(DeletePublicAssetsSuccessState())));
+      when(removeIdentityFromPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(RemoveIdentityFromPublicAssetsSuccessState())));
+      when(addIdentityToPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(AddIdentityToPublicAssetsSuccessState())));
+  
+      // act
+      await cleanUpPublicAssetsInteractor.execute(
+        session,
+        accountId,
+        identityId: identityId,
+        identityActionType: identityActionType,
+        publicAssetsInIdentityArguments: publicAssetsInIdentityArguments).last;
+      
+      // assert
+      verifyNever(
+        deletePublicAssetsInteractor.execute(
+          any,
+          any,
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+      verify(
+        removeIdentityFromPublicAssetsInteractor.execute(
+          session,
+          accountId,
+          identityId: identityId,
+          publicAssetIds: [toBeDeletedPublicAssetId])
+      ).called(1);
+      verifyNever(
+        addIdentityToPublicAssetsInteractor.execute(
+          any,
+          any,
+          identityId: anyNamed('identityId'),
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+    });
+
+    test(
+      'should add reference to public assets '
+      'when there are new public assets '
+      'and identity action is create',
+    () async {
+      // arrange
+      final identityId = IdentityId(Id('id-1'));
+      const identityActionType = IdentityActionType.create;
+      final newlyPickedPublicAssetIds = [Id('public-asset-1')];
+      final htmlSignature = '<img src="public-asset-1" public-asset-id="${newlyPickedPublicAssetIds[0].value}"/>';
+      final publicAssetsInIdentityArguments = PublicAssetsInIdentityArguments(
+        htmlSignature: htmlSignature,
+        preExistingPublicAssetIds: [],
+        newlyPickedPublicAssetIds: newlyPickedPublicAssetIds);
+
+      when(deletePublicAssetsInteractor
+        .execute(any, any, publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(DeletePublicAssetsSuccessState())));
+      when(removeIdentityFromPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(RemoveIdentityFromPublicAssetsSuccessState())));
+      when(addIdentityToPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(AddIdentityToPublicAssetsSuccessState())));
+  
+      // act
+      await cleanUpPublicAssetsInteractor.execute(
+        session,
+        accountId,
+        identityId: identityId,
+        identityActionType: identityActionType,
+        publicAssetsInIdentityArguments: publicAssetsInIdentityArguments).last;
+      
+      // assert
+      verifyNever(
+        deletePublicAssetsInteractor.execute(
+          any,
+          any,
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+      verifyNever(
+        removeIdentityFromPublicAssetsInteractor.execute(
+          any,
+          any,
+          identityId: anyNamed('identityId'),
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+      verify(
+        addIdentityToPublicAssetsInteractor.execute(
+          session,
+          accountId,
+          identityId: identityId,
+          publicAssetIds: newlyPickedPublicAssetIds)
+      );
+    });
+
+    test(
+      'should add reference to public assets '
+      'when there are new public assets '
+      'and those new public assets are pasted to signature',
+    () async {
+      // arrange
+      const identityActionType = IdentityActionType.create;
+      final identityId = IdentityId(Id('id-1'));
+      final pastedPublicAssetId = Id('public-asset-1');
+      final htmlSignature = '<img src="public-asset-1" public-asset-id="${pastedPublicAssetId.value}"/>';
+      final publicAssetsInIdentityArguments = PublicAssetsInIdentityArguments(
+        htmlSignature: htmlSignature,
+        preExistingPublicAssetIds: [],
+        newlyPickedPublicAssetIds: []);
+
+      when(deletePublicAssetsInteractor
+        .execute(any, any, publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(DeletePublicAssetsSuccessState())));
+      when(removeIdentityFromPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(RemoveIdentityFromPublicAssetsSuccessState())));
+      when(addIdentityToPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(AddIdentityToPublicAssetsSuccessState())));
+  
+      // act
+      await cleanUpPublicAssetsInteractor.execute(
+        session,
+        accountId,
+        identityId: identityId,
+        identityActionType: identityActionType,
+        publicAssetsInIdentityArguments: publicAssetsInIdentityArguments).last;
+      
+      // assert
+      verifyNever(
+        deletePublicAssetsInteractor.execute(
+          any,
+          any,
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+      verifyNever(
+        removeIdentityFromPublicAssetsInteractor.execute(
+          any,
+          any,
+          identityId: anyNamed('identityId'),
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+      verify(
+        addIdentityToPublicAssetsInteractor.execute(
+          session,
+          accountId,
+          identityId: identityId,
+          publicAssetIds: [pastedPublicAssetId])
+      );
+    });
+
+    test(
+      'should do nothing '
+      'when there is no new public assets '
+      'and there is no change in old public assets '
+      'and there is no pasted public assets in signature',
+    () async {
+      // arrange
+      const identityActionType = IdentityActionType.create;
+      final identityId = IdentityId(Id('id-1'));
+      final oldPublicAssetId = Id('public-asset-1');
+      final htmlSignature = '<img src="public-asset-1" public-asset-id="${oldPublicAssetId.value}"/>';
+      final publicAssetsInIdentityArguments = PublicAssetsInIdentityArguments(
+        htmlSignature: htmlSignature,
+        preExistingPublicAssetIds: [oldPublicAssetId],
+        newlyPickedPublicAssetIds: []);
+
+      when(deletePublicAssetsInteractor
+        .execute(any, any, publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(DeletePublicAssetsSuccessState())));
+      when(removeIdentityFromPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(RemoveIdentityFromPublicAssetsSuccessState())));
+      when(addIdentityToPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(AddIdentityToPublicAssetsSuccessState())));
+  
+      // act
+      await cleanUpPublicAssetsInteractor.execute(
+        session,
+        accountId,
+        identityId: identityId,
+        identityActionType: identityActionType,
+        publicAssetsInIdentityArguments: publicAssetsInIdentityArguments).last;
+      
+      // assert
+      verifyNever(
+        deletePublicAssetsInteractor.execute(
+          any,
+          any,
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+      verifyNever(
+        removeIdentityFromPublicAssetsInteractor.execute(
+          any,
+          any,
+          identityId: anyNamed('identityId'),
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+      verifyNever(
+        addIdentityToPublicAssetsInteractor.execute(
+          session,
+          accountId,
+          identityId: identityId,
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+    });
+
+    test(
+      'should destroy unused public assets '
+      'when there are picked public assets that are deleted '
+      'and add reference to public assets '
+      'when there are new public assets '
+      'and identity action is create'
+      'and add reference to public assets '
+      'when there are new public assets '
+      'and those new public assets are pasted to signature',
+    () async {
+      // arrange
+      final identityId = IdentityId(Id('id-1'));
+      const identityActionType = IdentityActionType.create;
+      final toBeUsedNewlyPickedPublicAssetId = Id('public-asset-1');
+      final toBeDeletedNewlyPickedPublicAssetId = Id('public-asset-2');
+      final newlyPickedPublicAssetIds = [
+        toBeUsedNewlyPickedPublicAssetId,
+        toBeDeletedNewlyPickedPublicAssetId
+      ];
+      final pastedPublicAssetId = Id('public-asset-3');
+      final htmlSignature = '<img src="public-asset-1" public-asset-id="${toBeUsedNewlyPickedPublicAssetId.value}"/>'
+        '<img src="public-asset-3" public-asset-id="${pastedPublicAssetId.value}"/>';
+      final publicAssetsInIdentityArguments = PublicAssetsInIdentityArguments(
+        htmlSignature: htmlSignature,
+        preExistingPublicAssetIds: [],
+        newlyPickedPublicAssetIds: newlyPickedPublicAssetIds);
+
+      when(deletePublicAssetsInteractor
+        .execute(any, any, publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(DeletePublicAssetsSuccessState())));
+      when(removeIdentityFromPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(RemoveIdentityFromPublicAssetsSuccessState())));
+      when(addIdentityToPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(AddIdentityToPublicAssetsSuccessState())));
+  
+      // act
+      await cleanUpPublicAssetsInteractor.execute(
+        session,
+        accountId,
+        identityId: identityId,
+        identityActionType: identityActionType,
+        publicAssetsInIdentityArguments: publicAssetsInIdentityArguments).last;
+      
+      // assert
+      verify(
+        deletePublicAssetsInteractor.execute(
+          session,
+          accountId,
+          publicAssetIds: [toBeDeletedNewlyPickedPublicAssetId])
+      ).called(1);
+      verifyNever(
+        removeIdentityFromPublicAssetsInteractor.execute(
+          any,
+          any,
+          identityId: anyNamed('identityId'),
+          publicAssetIds: anyNamed('publicAssetIds'))
+      );
+      verify(
+        addIdentityToPublicAssetsInteractor.execute(
+          session,
+          accountId,
+          identityId: identityId,
+          publicAssetIds: [pastedPublicAssetId, toBeUsedNewlyPickedPublicAssetId])
+      ).called(1);
+    });
+
+    test(
+      'should destroy unused public assets '
+      'when there are picked public assets that are deleted '
+      'and remove reference to public assets '
+      'when there are old public assets that are deleted '
+      'and add reference to public assets '
+      'when there are new public assets '
+      'and those new public assets are pasted to signature',
+    () async {
+      // arrange
+      final identityId = IdentityId(Id('id-1'));
+      const identityActionType = IdentityActionType.edit;
+      final toBeUsedNewlyPickedPublicAssetId = Id('public-asset-1');
+      final toBeDeletedNewlyPickedPublicAssetId = Id('public-asset-2');
+      final newlyPickedPublicAssetIds = [
+        toBeUsedNewlyPickedPublicAssetId,
+        toBeDeletedNewlyPickedPublicAssetId
+      ];
+      final toBeDeletedPreExistingPublicAssetId = Id('public-asset-3');
+      final pastedPublicAssetId = Id('public-asset-4');
+      final htmlSignature = '<img src="public-asset-1" public-asset-id="${toBeUsedNewlyPickedPublicAssetId.value}"/>'
+        '<img src="public-asset-4" public-asset-id="${pastedPublicAssetId.value}"/>';
+      final publicAssetsInIdentityArguments = PublicAssetsInIdentityArguments(
+        htmlSignature: htmlSignature,
+        preExistingPublicAssetIds: [toBeDeletedPreExistingPublicAssetId],
+        newlyPickedPublicAssetIds: newlyPickedPublicAssetIds);
+
+      when(deletePublicAssetsInteractor
+        .execute(any, any, publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(DeletePublicAssetsSuccessState())));
+      when(removeIdentityFromPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(RemoveIdentityFromPublicAssetsSuccessState())));
+      when(addIdentityToPublicAssetsInteractor
+        .execute(any, any, identityId: anyNamed('identityId'), publicAssetIds: anyNamed('publicAssetIds')))
+        .thenAnswer((_) => Stream.value(Right(AddIdentityToPublicAssetsSuccessState())));
+  
+      // act
+      await cleanUpPublicAssetsInteractor.execute(
+        session,
+        accountId,
+        identityId: identityId,
+        identityActionType: identityActionType,
+        publicAssetsInIdentityArguments: publicAssetsInIdentityArguments).last;
+      
+      // assert
+      verify(
+        deletePublicAssetsInteractor.execute(
+          session,
+          accountId,
+          publicAssetIds: [toBeDeletedNewlyPickedPublicAssetId])
+      ).called(1);
+      verify(
+        removeIdentityFromPublicAssetsInteractor.execute(
+          session,
+          accountId,
+          identityId: identityId,
+          publicAssetIds: [toBeDeletedPreExistingPublicAssetId])
+      ).called(1);
+      verify(
+        addIdentityToPublicAssetsInteractor.execute(
+          session,
+          accountId,
+          identityId: identityId,
+          publicAssetIds: [pastedPublicAssetId])
+      ).called(1);
+    });
+  });
+}
\ No newline at end of file