Reveal safe diagnostic data

Technical lifecycle metadata is available automatically. Application values remain hidden until the UseCase explicitly encodes a JSON-safe representation.

final class CartUseCase extends UseCase<CartState>
    with UseCaseDiagnosticsDataProvider {
  @override
  Object? encodeUseCaseDiagnosticValue(
    UseCaseDiagnosticValueKind kind,
    Object? value,
  ) {
    if (kind == UseCaseDiagnosticValueKind.state && value is CartState) {
      return {'itemCount': value.itemCount};
    }
    return null;
  }
}

Import package:usecase_forge/diagnostics.dart. Return null for secrets, tokens, personal data, large payloads, and types that are not needed for the investigation. A formatter failure is isolated from Command execution.