flutterのログ周りを綺麗に定義する

logger.dart

final logger = Logger(
  output: CrashlyticsLogger(),
  printer: PrettyPrinter(
    methodCount: 1,
    errorMethodCount: 5,
    dateTimeFormat: DateTimeFormat.onlyTimeAndSinceStart,
  ),
);

class CrashlyticsLogger extends LogOutput {
  @override
  void output(OutputEvent event) {
    for (final e in event.lines) {
      dev.log(e, name: 'logger');
    }
    _sendCrashlytics(event);
  }

  Future<void> _sendCrashlytics(OutputEvent event) async {
    try {
      if (Firebase.apps.isEmpty) return;

      if (event.level.isSerious(Level.error)) {
        await FirebaseCrashlytics.instance.recordError(
          event.origin.error,
          event.origin.stackTrace,
          reason: event.origin.message,
          printDetails: true,
          fatal: event.level == Level.fatal,
        );
      } else if (event.level.isSerious(Level.info)) {
        await FirebaseCrashlytics.instance.log(event.origin.message.toString());
      }
    } catch (e) {
      dev.log('logの出力エラー', name: 'logger');
    }
  }
}

extension _LevelExt on Level {
  bool isSerious(Level level) {
    return value >= level.value;
  }
}

extension AnalyticsLogExt on Logger {
  Future<void> setUserId(String? id) async {
    try {
      if (Firebase.apps.isEmpty) return;
      await FirebaseAnalytics.instance.setUserId(id: id);
      await FirebaseCrashlytics.instance.setUserIdentifier(id ?? '');
    } catch (e, s) {
      logger.e('failed set userId.', error: e, stackTrace: s);
    }
  }

  Future<void> setUserProperty({
    required UserProperty property,
    required String? value,
  }) async {
    try {
      if (Firebase.apps.isEmpty) return;
      await FirebaseAnalytics.instance.setUserProperty(
        name: property.name,
        value: value,
      );
      await FirebaseCrashlytics.instance.setCustomKey(
        property.name,
        value ?? '',
      );
    } catch (e, s) {
      logger.e('failed set user property.', error: e, stackTrace: s);
    }
  }
}

sealed class UserProperty {
  final String name;

  UserProperty({required this.name});
}