選擇優勝者彩票測試投擲； 錯誤：事務已被 EVM 還原：

Question

我正在寫一份彩票合同，該合同應該接受玩家，選擇贏家並將收集到的資金發送到贏家的地址，然后重新開始。 運行 npm 運行測試后，前 5 個測試通過，但“將錢發送給獲勝者並重置玩家數組”測試失敗，錯誤消息如下。

  1) lottery Contract
   sends money to the winner & resets the players array:
 Error: Transaction has been reverted by the EVM:

就我個人而言，我認為問題出在文件 Lottery.test.js 上，因為到目前為止，一切都運行良好；

await lottery.methods.pickWinner().send({
        from: accounts[0]
    });

其他項目文件粘貼在下面以幫助調試。

我的 Lottery.sol 文件；

    pragma solidity ^0.8.13;

contract Lottery {
    address public manager;
    address payable[] public players;

    function myLottery() public {
        manager = msg.sender;
    }

    function enter() public payable {
        require(msg.value > .001 ether);
        players.push(payable(msg.sender));
    }

    function random() private view returns(uint){
        return uint(keccak256(abi.encodePacked(block.difficulty, block.timestamp, players)));
    }

    function pickWinner() public restricted{
        uint index = random() % players.length;
        players[index].transfer(address(this).balance);  
        players = new address payable[](0);
    }

    modifier restricted() {
        require(msg.sender == manager);
        _;
    }

    function getPlayers() public view returns (address payable[] memory) {
        return players;
    }
}

編譯.js

    const path = require("path");
const fs = require("fs");
const solc = require("solc");

const lotteryPath = path.resolve(__dirname, "contracts", "Lottery.sol");
const source = fs.readFileSync(lotteryPath, "utf8");

let input = {
  language: "Solidity",
  sources: {
    [lotteryPath]: {
      content: source,
    },
  },

  settings: {
    outputSelection: {
      "*": {
        "*": ["*"],
      },
    },
  },
};

var output = JSON.parse(solc.compile(JSON.stringify(input)));

module.exports = {
  abi: output.contracts[[lotteryPath]]["Lottery"].abi,
  bytecode: output.contracts[[lotteryPath]]["Lottery"].evm.bytecode.object,
};

部署.js

    const HDWalletProvider = require('truffle-hdwallet-provider');
const Web3 = require('web3');
const { abi, bytecode } = require("./compile");

const provider = new HDWalletProvider(
    '****myMneumonic*****',
    '****myInfuraNode****'
);

const web3 = new Web3 (provider);

const deploy = async () => {
    const accounts = await web3.eth.getAccounts();

    console.log('Attempting to deploy from account;', accounts[0]);

    const result = await new web3.eth.Contract(abi)
    .deploy({ data: bytecode })
    .send({ from: accounts[0], gas: '10000000', gasPrice: '2000000000'});

    console.log('Contract deployed to;', result.options.address);
};
deploy();

彩票.test.js

    const assert = require("assert");
const ganache = require("ganache");
const Web3 = require("web3");
const web3 = new Web3(ganache.provider());
const { abi, bytecode } = require("../compile");

let accounts;
let lottery;

beforeEach(async () => {
  //get a list of all accounts
  accounts = await web3.eth.getAccounts();

  lottery = await new web3.eth.Contract(abi)
    .deploy({ data: bytecode })
    .send({ from: accounts[0], gas: "1000000" });
});

describe('lottery Contract', () => {
    it ('deploys a contract', () => {
        assert.ok(lottery.options.address);
    });

    it('allows one account to enter', async () => {
        await lottery.methods.enter().send({
            from: accounts[0],
            value: web3.utils.toWei('0.002', 'ether')
        });

        const players = await lottery.methods.getPlayers().call({
            from: accounts [0]
        });

        assert.equal(accounts[0], players);
        assert.equal(1, players.length);
    });

    it('allows multiple accounts to enter', async () => {
        await lottery.methods.enter().send({
            from: accounts[0],
            value: web3.utils.toWei('0.002', 'ether')
        });

        await lottery.methods.enter().send({
            from: accounts[1],
            value: web3.utils.toWei('0.002', 'ether')
        });

        await lottery.methods.enter().send({
            from: accounts[2],
            value: web3.utils.toWei('0.002', 'ether')
        });

        const players = await lottery.methods.getPlayers().call({
            from: accounts[0]
        });

        assert.equal(accounts[0], players[0]);
        assert.equal(accounts[1], players[1]);
        assert.equal(accounts[2], players[2]);
        assert.equal(3, players.length);
    });

    it('requires a minimum amount of ether to enter', async () => {
        try {
            await lottery.methods.enter().send({
                from: accounts[0],
                value: 200
            });
            assert(false);
        } catch (err) {
            assert(err);
        }
    });

    it ('only manager can call pickWinner', async () => {
        try {
            await lottery.methods.pickWinner().send({
                from: accounts[1],
                value: 200
            });
            assert(false);
        } catch (err) {
            assert(err);
        }
    });

    it('sends money to the winner & resets the players array', async () =>{
        await lottery.methods.enter().send({
            from: accounts[0],
            value: web3.utils.toWei('1', 'ether')
        });

        const initialBalance = await web3.eth.getBalance(accounts[0]);

        await lottery.methods.pickWinner().send({
            from: accounts[0]
        });

        const finalBalance = await web3.eth.getBalance(accounts[0]);

        const difference = finalBalance - initialBalance;
        console.log(difference);
        assert(difference > web3.utils.toWei('0.8', 'ether'));
    });
}); 

Answer 1

您面臨的問題是，在嘗試挑選獲勝者之前，您實際上從未設置過經理角色。 它失敗是因為在調用pickWinner()方法時，您的經理地址是 null，並且這會因您的restricted修飾符中的 require 語句而失敗。 我還要指出，允許任何人設置經理角色可能不是您想要做的事情。 相反，您應該在部署合同時在合同構造函數中設置經理角色，如下所示：

constructor(){
  manager = msg.sender;
}

然后你可以一起擺脫myLottery() 。 希望這有所幫助。 如果您有任何其他問題，請隨時通過 Twitter @_syndk8 與我聯系。