workavia-mail-front/lib/main/error/capability_validator.dart

import 'package:core/utils/app_logger.dart';
import 'package:jmap_dart_client/jmap/account_id.dart';
import 'package:jmap_dart_client/jmap/core/capability/capability_identifier.dart';
import 'package:jmap_dart_client/jmap/core/session/session.dart';
import 'package:tmail_ui_user/main/error/request_error.dart';

void requireCapability(Session session, AccountId accountId, List<CapabilityIdentifier> requiredCapabilities) {
  final account = session.accounts[accountId];
  if (account == null) {
    throw const InvalidCapability();
  }

  final matchedCapabilities = account.accountCapabilities.keys
      .fold<Set<CapabilityIdentifier>>(
        <CapabilityIdentifier>{},
        (previousValue, element) {
          if (requiredCapabilities.contains(element)) {
            previousValue.add(element);
          }
          return previousValue;
        }
      );
  final missingCapabilities = requiredCapabilities.toSet().difference(matchedCapabilities);
  if (missingCapabilities.isNotEmpty) {
    throw SessionMissingCapability(missingCapabilities);
  }
}

extension CapabilityIdentifierExtension on List<CapabilityIdentifier> {

  bool isSupported(Session session, AccountId accountId) {
    try {
      requireCapability(session, accountId, this);
      return true;
    } catch (error) {
      logError('CapabilityIdentifierExtension::isSupported(): $error');
      return false;
    }
  }
}