Return Reason for Forwarder Contract Execution

As we dive into the code, let’s first try to understand why the forwarder.execute function is reverting. More specifically, I’ll examine the reason for the revertReason and provide suggestions for resolving it.

pragma strength ^0,8,0;
contract Forwarder {
// Forwarder contract logic
function joinChallenge(uint256 _challenge) public view returns (bool): string memory {
// Some forwarder logic here...
// The user signs the authorization request and we return a successful result
bool success = true;
return success;
}
function execute() public onlyOwner {
// This is where the rollback happens...
// The "joinChallenge" function calls "forwarder.joinChallenge"
// Here's what can cause a rollback:
// 1. Invalid input: If _challenge is not a valid index for the challenge set.
// Solitude returns an error message
// "The arguments passed to JoinChallenge are invalid."
revertReason = "Invalid challenge index";
// 2. Gas limitations: The JoinChallenge function may exceed the allowed gas limit.
// The cost of the JoinChallenge call may be too high, causing the contract to consume its resources.
// In this case, Solitude returns an error message
revertReason = "Gas consumption exceeded";
// 3. Forwarder logic: If there is a problem with the forwarder's operation,
// it can cause a rollback in joinChallenge.
// This may trigger this:
// 1. Internal error: The forwarder has encountered an internal error.
// This can be caused by a number of factors, such as faulty logic or an incorrect assumption.
revertReason = "Internal forwarding error";
// If a rollback occurs, we need to handle it properly
if (revertReason != "Invalid challenge index") {
// Handle the rollback in the joinChallenge function...
// Check for gas limit constraints
gasLimitCheck();
}
}

Workarounds

• Input check: Check the _challenge input to ensure that it is a valid array index or a specific value that can be passed to joinChallenge.

• Gas limit constraints: Ensure that the forwarder.joinChallenge function has sufficient gas limits in place to handle calls from the forwarder contract.

• Forwarder Logic Checks: Implement checks in your forwarder logic to detect and prevent internal errors, such as incorrect assumptions or faulty logic.

Additional Guidance

• Monitor your forwarder logs for any issues that might be causing rollbacks.

• Check the gas cost of the “joinChallenge” to ensure that it is reasonable and does not exceed the allowed limit.

• Test your forwarder contract thoroughly to identify any regressions or edge cases.

• Consider implementing more robust input validation, gas limits, and error detection mechanisms to prevent rollbacks in the future.

By addressing these areas, you should be able to resolve the reason for the forwarder.execute rollback and ensure reliable execution of the joinChallenge function.