feat(account_repository): Allow registering callback to be executed b…

…efore an account is logged out

Signed-off-by: provokateurin <kate@provokateurin.de>

packages/neon_framework/packages/account_repository/lib/src/account_repository.dart

@@ -14,6 +14,9 @@ import 'package:rxdart/rxdart.dart';
 
 part 'account_storage.dart';
 
+/// Signature of a callback that executed right before the [account] is logged out.
+typedef BeforeLogOutCallback = Future<void> Function(Account account);
+
 /// {@template account_failure}
 /// A base failure for the account repository failures.
 /// {@endtemplate}
@@ -86,6 +89,7 @@ class AccountRepository {
   final String _userAgent;
   final http.Client _httpClient;
   final AccountStorage _storage;
+  final List<BeforeLogOutCallback> _beforeLogOutCallbacks = [];
 
   final BehaviorSubject<({String? active, BuiltMap<String, Account> accounts})> _accounts =
       BehaviorSubject.seeded((active: null, accounts: BuiltMap()));
@@ -272,6 +276,18 @@ class AccountRepository {
     ]);
   }
 
+  /// Registers a new [callback] that is executed right before an account is logged out.
+  ///
+  /// The callback must not throw any exceptions and handle them gracefully itself.
+  void registerBeforeLogOutCallback(BeforeLogOutCallback callback) {
+    _beforeLogOutCallbacks.add(callback);
+  }
+
+  /// Unregisters a [callback] that was previously registered with [registerBeforeLogOutCallback].
+  void unregisterBeforeLogOutCallback(BeforeLogOutCallback callback) {
+    _beforeLogOutCallbacks.remove(callback);
+  }
+
   /// Logs out the user from the server.
   ///
   /// May throw a [DeleteCredentialsFailure].
@@ -299,8 +315,12 @@ class AccountRepository {
 
     _accounts.add((active: active, accounts: accounts));
 
+    for (final callback in _beforeLogOutCallbacks) {
+      await callback(account!);
+    }
+
     try {
-      await account?.client.authentication.appPassword.deleteAppPassword();
+      await account!.client.authentication.appPassword.deleteAppPassword();
     } on http.ClientException catch (error, stackTrace) {
       Error.throwWithStackTrace(DeleteCredentialsFailure(error), stackTrace);
     }

packages/neon_framework/packages/account_repository/test/account_repository_test.dart

@@ -40,6 +40,12 @@ class _UsersClientMock extends Mock implements provisioning_api.$UsersClient {}
 
 class _AccountStorageMock extends Mock implements AccountStorage {}
 
+class _FakeAccount extends Fake implements Account {}
+
+class _BeforeLogOutCallbackMock extends Mock {
+  Future<void> call(Account account);
+}
+
 typedef _AccountStream = ({BuiltList<Account> accounts, Account? active});
 
 void main() {
@@ -54,6 +60,7 @@ void main() {
   setUpAll(() {
     registerFallbackValue(_FakeUri());
     registerFallbackValue(_FakePollRequest());
+    registerFallbackValue(_FakeAccount());
     MockNeonStorage();
   });
 
@@ -506,6 +513,20 @@ void main() {
         when(() => appPassword.deleteAppPassword()).thenAnswer(
           (_) async => _DynamiteResponseMock<core.AppPasswordDeleteAppPasswordResponseApplicationJson, void>(),
         );
+
+        final callback1 = _BeforeLogOutCallbackMock();
+        when(() => callback1.call(any())).thenAnswer((_) async {});
+        repository.registerBeforeLogOutCallback(callback1.call);
+
+        final callback2 = _BeforeLogOutCallbackMock();
+        repository
+          ..registerBeforeLogOutCallback(callback2.call)
+          ..unregisterBeforeLogOutCallback(callback2.call);
+
+        final callback3 = _BeforeLogOutCallbackMock();
+        when(() => callback3.call(any())).thenAnswer((_) async {});
+        repository.registerBeforeLogOutCallback(callback3.call);
+
         await repository.logOut(credentialsList.first.id);
 
         await expectLater(
@@ -517,6 +538,10 @@ void main() {
           ),
         );
 
+        verify(() => callback1(accountsList.first)).called(1);
+        verifyNever(() => callback2(accountsList.first));
+        verify(() => callback3(accountsList.first)).called(1);
+
         verify(() => appPassword.deleteAppPassword()).called(1);
         verify(() => storage.saveLastAccount(credentialsList[1].id)).called(1);
         verify(() => storage.saveCredentials(any(that: equals([credentialsList[1]])))).called(1);