Differences between mine and Filip’s:
- -I created a “signers” mapping from addresses to bool. This moves the loop over the input signer address array from the modifier which runs constantly to the constructor that runs once.
- -I thought it was safe to presume signers creating transfer requests intend them to be signed by themselves immediately.
- -Added a “dissaprove()” function for signers to change their mind with (before its too late).
- -Added a check vs. the wallet’s balance upon creating or approving transfer requests. You should never be able to request more ether be transfered than is in the wallet. And if the wallet balance drops via another transfer all existing yet unsent transfers larger than the current wallet ballance cannot be approved. Funds can be added via deposit(), or the default recieve().
- -Added getLimit() and getBalance() hooks for chai/waffle testing.
- -Running 0.8.0.
pragma solidity 0.8.0;
pragma abicoder v2;
import "hardhat/console.sol";
import "./inherited/Ownable.sol";
// SPDX-License-Identifier: UNLICENSED
// Multi-Signature Wallet
// For Ivan on Tech Academy
// Solidity 101 Project
// Solution by Bob Clark
contract Wallet {
struct Transfer{
uint amount;
address payable receiver;
uint approvals;
bool hasBeenSent;
uint id;
}
Transfer[] transferRequests;
mapping(address => bool) signers;
mapping(address => mapping(uint => bool)) approvals;
uint limit;
event RqstCreated(uint _id, uint _amount, address _initiator, address _receiver);
event RqstApprvd(uint _id, uint _approvals, address _approver);
event RqstUnApprvd(uint _id, uint _approvals, address _approver);
event RqstSent(uint _id);
//Should only allow people in the signers list to continue the execution.
modifier onlySigners(){
require(signers[msg.sender] = true, "Not a signer.");
_;
}
//Should initialize the signers list and the limit
constructor(address[] memory _signers, uint _limit) {
for (uint i=0; i<_signers.length; i++) {
signers[_signers[i]] = true;
}
limit = _limit;
}
//Empty function
function deposit() public payable {}
//Create an instance of the Transfer struct and add it to the transferRequests array
function createTransfer(uint _amount, address payable _receiver) public onlySigners {
require(_amount <= address(this).balance,"Insufficient Funds.");
uint id = transferRequests.length;
transferRequests.push(Transfer(_amount, _receiver, 1, false, id));
approvals[msg.sender][id] = true;
emit RqstCreated(transferRequests.length, _amount, msg.sender, _receiver);
}
//Set your approval for one of the transfer requests.
//Need to update the Transfer object.
//Need to update the mapping to record the approval for the msg.sender.
//When the amount of approvals for a transfer has reached the limit, this function should send the transfer to the recipient.
//An owner should not be able to vote twice.
//An owner should not be able to vote on a tranfer request that has already been sent.
function approve(uint _id) public onlySigners {
require(approvals[msg.sender][_id] == false,"Already approved.");
require(transferRequests[_id].hasBeenSent == false, "Already Sent.");
require(transferRequests[_id].amount <= address(this).balance, "Insufficient Funds.");
approvals[msg.sender][_id] = true;
transferRequests[_id].approvals++;
emit RqstApprvd(_id, transferRequests[_id].approvals, msg.sender);
if(transferRequests[_id].approvals >= limit){
transferRequests[_id].hasBeenSent = true;
transferRequests[_id].receiver.transfer(transferRequests[_id].amount);
emit RqstSent(_id);
}
}
// Undo!
function disapprove(uint _id) public onlySigners {
require(approvals[msg.sender][_id] == true,"Already unapproved.");
require(transferRequests[_id].hasBeenSent == false, "Already Sent.");
approvals[msg.sender][_id] = false;
transferRequests[_id].approvals--;
emit RqstUnApprvd(_id, transferRequests[_id].approvals, msg.sender);
}
//Should return all transfer requests
function getTransferRequests() public view returns (Transfer[] memory){
return transferRequests;
}
// Testing hook.
// Note: signer addresses cannot be recovered from mapping
function getLimit() public view returns (uint) {
return limit;
}
// Testing hook.
function getBalance() public view returns(uint) {
return address(this).balance;
}
}
