Debt DAO contest - d3e4's results

function receiveTokenOrETH(
      address token,
      address sender,
      uint256 amount
    )
      external
      returns (bool)
    {
        if(token == address(0)) { revert TransferFailed(); }
        if(token != Denominations.ETH) { // ERC20
            IERC20(token).safeTransferFrom(sender, address(this), amount);
        } else { // ETH
            if(msg.value < amount) { revert TransferFailed(); }
        }
        return true;
    }

/**
* @notice - Send ETH or ERC20 token from this contract to an external contract
* @param token - address of token to send out. Denominations.ETH for raw ETH
* @param receiver - address to send tokens to
* @param amount - amount of tokens to send
*/
function sendOutTokenOrETH(
    address token,
    address receiver,
    uint256 amount
)
    external
    returns (bool)
{
    if(token == address(0)) { revert TransferFailed(); }
    
    // both branches revert if call failed
    if(token!= Denominations.ETH) { // ERC20
        IERC20(token).safeTransfer(receiver, amount);
    } else { // ETH
        payable(receiver).transfer(amount);
    }
    return true;
}