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joeizang/3_Ballot.sol

Created August 12, 2024 11:48
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Created using remix-ide: Realtime Ethereum Contract Compiler and Runtime. Load this file by pasting this gists URL or ID at https://remix.ethereum.org/#version=soljson-v0.8.26+commit.8a97fa7a.js&optimize=false&runs=200&gist=
Raw
3_Ballot.sol
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;
/**
* @title Ballot
* @dev Implements voting process along with vote delegation
*/
contract Ballot {
struct Voter {
uint weight; // weight is accumulated by delegation
bool voted; // if true, that person already voted
address delegate; // person delegated to
uint vote; // index of the voted proposal
}
struct Proposal {
// If you can limit the length to a certain number of bytes,
// always use one of bytes1 to bytes32 because they are much cheaper
bytes32 name; // short name (up to 32 bytes)
uint voteCount; // number of accumulated votes
}
address public chairperson;
mapping(address => Voter) public voters;
Proposal[] public proposals;
/**
* @dev Create a new ballot to choose one of 'proposalNames'.
* @param proposalNames names of proposals
*/
constructor(bytes32[] memory proposalNames) {
chairperson = msg.sender;
voters[chairperson].weight = 1;
for (uint i = 0; i < proposalNames.length; i++) {
// 'Proposal({...})' creates a temporary
// Proposal object and 'proposals.push(...)'
// appends it to the end of 'proposals'.
proposals.push(Proposal({
name: proposalNames[i],
voteCount: 0
}));
}
}
/**
* @dev Give 'voter' the right to vote on this ballot. May only be called by 'chairperson'.
* @param voter address of voter
*/
function giveRightToVote(address voter) public {
require(
msg.sender == chairperson,
"Only chairperson can give right to vote."
);
require(
!voters[voter].voted,
"The voter already voted."
);
require(voters[voter].weight == 0);
voters[voter].weight = 1;
}
/**
* @dev Delegate your vote to the voter 'to'.
* @param to address to which vote is delegated
*/
function delegate(address to) public {
Voter storage sender = voters[msg.sender];
require(!sender.voted, "You already voted.");
require(to != msg.sender, "Self-delegation is disallowed.");
while (voters[to].delegate != address(0)) {
to = voters[to].delegate;
// We found a loop in the delegation, not allowed.
require(to != msg.sender, "Found loop in delegation.");
}
sender.voted = true;
sender.delegate = to;
Voter storage delegate_ = voters[to];
if (delegate_.voted) {
// If the delegate already voted,
// directly add to the number of votes
proposals[delegate_.vote].voteCount += sender.weight;
} else {
// If the delegate did not vote yet,
// add to her weight.
delegate_.weight += sender.weight;
}
}
/**
* @dev Give your vote (including votes delegated to you) to proposal 'proposals[proposal].name'.
* @param proposal index of proposal in the proposals array
*/
function vote(uint proposal) public {
Voter storage sender = voters[msg.sender];
require(sender.weight != 0, "Has no right to vote");
require(!sender.voted, "Already voted.");
sender.voted = true;
sender.vote = proposal;
// If 'proposal' is out of the range of the array,
// this will throw automatically and revert all
// changes.
proposals[proposal].voteCount += sender.weight;
}
/**
* @dev Computes the winning proposal taking all previous votes into account.
* @return winningProposal_ index of winning proposal in the proposals array
*/
function winningProposal() public view
returns (uint winningProposal_)
{
uint winningVoteCount = 0;
for (uint p = 0; p < proposals.length; p++) {
if (proposals[p].voteCount > winningVoteCount) {
winningVoteCount = proposals[p].voteCount;
winningProposal_ = p;
}
}
}
/**
* @dev Calls winningProposal() function to get the index of the winner contained in the proposals array and then
* @return winnerName_ the name of the winner
*/
function winnerName() public view
returns (bytes32 winnerName_)
{
winnerName_ = proposals[winningProposal()].name;
}
}
Raw
README.txt
REMIX DEFAULT WORKSPACE
Remix default workspace is present when:
i. Remix loads for the very first time
ii. A new workspace is created with 'Default' template
iii. There are no files existing in the File Explorer
This workspace contains 3 directories:
1. 'contracts': Holds three contracts with increasing levels of complexity.
2. 'scripts': Contains four typescript files to deploy a contract. It is explained below.
3. 'tests': Contains one Solidity test file for 'Ballot' contract & one JS test file for 'Storage' contract.
SCRIPTS
The 'scripts' folder has four typescript files which help to deploy the 'Storage' contract using 'web3.js' and 'ethers.js' libraries.
For the deployment of any other contract, just update the contract's name from 'Storage' to the desired contract and provide constructor arguments accordingly
in the file `deploy_with_ethers.ts` or `deploy_with_web3.ts`
In the 'tests' folder there is a script containing Mocha-Chai unit tests for 'Storage' contract.
To run a script, right click on file name in the file explorer and click 'Run'. Remember, Solidity file must already be compiled.
Output from script will appear in remix terminal.
Please note, require/import is supported in a limited manner for Remix supported modules.
For now, modules supported by Remix are ethers, web3, swarmgw, chai, multihashes, remix and hardhat only for hardhat.ethers object/plugin.
For unsupported modules, an error like this will be thrown: '<module_name> module require is not supported by Remix IDE' will be shown.
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