unhandled-promise.md

Unhandled promise's result

Configuration

• detector id: unhandled-promise
• severity: high

Description

Promise results should always be handled by a callback function or another promise. It is not recommended to leave promises unhandled in contracts. Otherwise, the changed state cannot be rolled back if the promise failed.

Sample code

token.ft_transfer_call(receiver, U128(amount), None, "".to_string());

In this sample, the contract invokes ft_transfer_call but doesn't handle its promise result with a specified callback function (e.g., resolve_transfer). Therefore, The contract won't know whether the transfer is successful. And if the transfer is failed, contract states will not be rolled back.