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yann300/README.txt

Created Apr 22, 2021
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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-v0.8.1+commit.df193b15.js&optimize=false&runs=200&gist=
REMIX EXAMPLE PROJECT
Remix example project is present when Remix loads very first time or there are no files existing in the File Explorer.
It contains 3 directories:
1. 'contracts': Holds three contracts with different complexity level, denoted with number prefix in file name.
2. 'scripts': Holds two scripts to deploy a contract. It is explained below.
3. 'tests': Contains one test file for 'Ballot' contract with unit tests in Solidity.
SCRIPTS
The 'scripts' folder contains example async/await scripts for deploying the 'Storage' contract.
For the deployment of any other contract, 'contractName' and 'constructorArgs' should be updated (along with other code if required).
Scripts have full access to the web3.js and ethers.js libraries.
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.
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;
/**
* @title Storage
* @dev Store & retrieve value in a variable
*/
contract Storage {
uint256 number;
/**
* @dev Store value in variable
* @param num value to store
*/
function store(uint256 num) public {
number = num;
}
/**
* @dev Return value
* @return value of 'number'
*/
function retrieve() public view returns (uint256){
return number;
}
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;
/**
* @title Owner
* @dev Set & change owner
*/
contract Owner {
address private owner;
// event for EVM logging
event OwnerSet(address indexed oldOwner, address indexed newOwner);
// modifier to check if caller is owner
modifier isOwner() {
// If the first argument of 'require' evaluates to 'false', execution terminates and all
// changes to the state and to Ether balances are reverted.
// This used to consume all gas in old EVM versions, but not anymore.
// It is often a good idea to use 'require' to check if functions are called correctly.
// As a second argument, you can also provide an explanation about what went wrong.
require(msg.sender == owner, "Caller is not owner");
_;
}
/**
* @dev Set contract deployer as owner
*/
constructor() {
owner = msg.sender; // 'msg.sender' is sender of current call, contract deployer for a constructor
emit OwnerSet(address(0), owner);
}
/**
* @dev Change owner
* @param newOwner address of new owner
*/
function changeOwner(address newOwner) public isOwner {
emit OwnerSet(owner, newOwner);
owner = newOwner;
}
/**
* @dev Return owner address
* @return address of owner
*/
function getOwner() external view returns (address) {
return owner;
}
}
// 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;
}
}
// Right click on the script name and hit "Run" to execute
(async () => {
try {
console.log('Running deployWithEthers script...')
const contractName = 'Storage' // Change this for other contract
const constructorArgs = [] // Put constructor args (if any) here for your contract
// Note that the script needs the ABI which is generated from the compilation artifact.
// Make sure contract is compiled and artifacts are generated
const artifactsPath = `browser/contracts/artifacts/${contractName}.json` // Change this for different path
const metadata = JSON.parse(await remix.call('fileManager', 'getFile', artifactsPath))
// 'web3Provider' is a remix global variable object
const signer = (new ethers.providers.Web3Provider(web3Provider)).getSigner()
let factory = new ethers.ContractFactory(metadata.abi, metadata.data.bytecode.object, signer);
let contract = await factory.deploy(...constructorArgs);
console.log('Contract Address: ', contract.address);
// The contract is NOT deployed yet; we must wait until it is mined
await contract.deployed()
console.log('Deployment successful.')
} catch (e) {
console.log(e.message)
}
})()
// Right click on the script name and hit "Run" to execute
(async () => {
try {
console.log('Running deployWithWeb3 script...')
const contractName = 'Storage' // Change this for other contract
const constructorArgs = [] // Put constructor args (if any) here for your contract
// Note that the script needs the ABI which is generated from the compilation artifact.
// Make sure contract is compiled and artifacts are generated
const artifactsPath = `browser/contracts/artifacts/${contractName}.json` // Change this for different path
const metadata = JSON.parse(await remix.call('fileManager', 'getFile', artifactsPath))
const accounts = await web3.eth.getAccounts()
let contract = new web3.eth.Contract(metadata.abi)
contract = contract.deploy({
data: metadata.data.bytecode.object,
arguments: constructorArgs
})
const newContractInstance = await contract.send({
from: accounts[0],
gas: 1500000,
gasPrice: '30000000000'
})
console.log('Contract deployed at address: ', newContractInstance.options.address)
} catch (e) {
console.log(e.message)
}
})()
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;
import "remix_tests.sol"; // this import is automatically injected by Remix.
import "../contracts/3_Ballot.sol";
contract BallotTest {
bytes32[] proposalNames;
Ballot ballotToTest;
function beforeAll () public {
proposalNames.push(bytes32("candidate1"));
ballotToTest = new Ballot(proposalNames);
}
function checkWinningProposal () public {
ballotToTest.vote(0);
Assert.equal(ballotToTest.winningProposal(), uint(0), "proposal at index 0 should be the winning proposal");
Assert.equal(ballotToTest.winnerName(), bytes32("candidate1"), "candidate1 should be the winner name");
}
function checkWinninProposalWithReturnValue () public view returns (bool) {
return ballotToTest.winningProposal() == 0;
}
}
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