javascript - 一个简单的 Solidity 合约和脚本的无效操作码错误

Question

我是 Solidity 和 web3.js 的新手。我正在按照这里的教程 -

https://medium.com/@mvmurthy/full-stack-hello-world-voting-ethereum-dapp-tutorial-part-1-40d2d0d807c2

构建一个简单的投票 Dapp。 我已经使用 npm 在本地 node_modules 文件夹中安装了 ganache-cli、solc 和 web3 版本 0.20.2。 Solidity 中的 Voting.sol 合约是:

pragma solidity ^0.4.18;

contract Voting {

  mapping (bytes32 => uint8) public votesReceived;
  bytes32[] public candidateList;

  function Voting(bytes32[] candidateNames) public {
    candidateList = candidateNames;
  }

  function totalVotesFor(bytes32 candidate) view public returns (uint8) {
    return votesReceived[candidate];
  }
}

使用以下名为 voting_main.js 的脚本:

Web3 = require('web3')
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"))

fs = require('fs')
code = fs.readFileSync('Voting.sol').toString()

solc = require('solc')
compiledCode = solc.compile(code)

abiDefinition = JSON.parse(compiledCode.contracts[':Voting'].interface)
VotingContract = web3.eth.contract(abiDefinition)
byteCode = compiledCode.contracts[':Voting'].bytecode
deployedContract = VotingContract.new(['Rama','Nick','Jose'],{data: byteCode, from: web3.eth.accounts[0], gas: 4700000})
contractInstance = VotingContract.at(deployedContract.address)

contractInstance.totalVotesFor.call('Rama')

当我在 localhost:8545 上运行 ganache-cli 然后在另一个终端运行脚本时，我收到以下错误。

ameya@ameya-HP-ENVY-15-Notebook-PC:~/Fresh_install$ node voting_main.js 
/home/ameya/Fresh_install/node_modules/solc/soljson.js:1
(function (exports, require, module, __filename, __dirname) { var Module;if(!Module)Module=(typeof Module!=="undefined"?Module:null)||{};var moduleOverrides={};for(var key in Module){if(Module.hasOwnProperty(key)){moduleOverrides[key]=Module[key]}}var ENVIRONMENT_IS_WEB=typeof window==="object";var ENVIRONMENT_IS_WORKER=typeof importScripts==="function";var ENVIRONMENT_IS_NODE=typeof process==="object"&&typeof require==="function"&&!ENVIRONMENT_IS_WEB&&!ENVIRONMENT_IS_WORKER;var ENVIRONMENT_IS_SHELL=!ENVIRONMENT_IS_WEB&&!ENVIRONMENT_IS_NODE&&!ENVIRONMENT_IS_WORKER;if(ENVIRONMENT_IS_NODE){if(!Module["print"])Module["print"]=function print(x){process["stdout"].write(x+"\n")};if(!Module["printErr"])Module["printErr"]=function printErr(x){process["stderr"].write(x+"\n")};var nodeFS=require("fs");var nodePath=require("path");Module["read"]=function read(filename,binary){filename=nodePath["normalize"](filename);var ret=nodeFS["readFileSync"](filename);if(!r

Error: VM Exception while processing transaction: invalid opcode
    at Object.InvalidResponse (/home/ameya/Fresh_install/node_modules/web3/lib/web3/errors.js:38:16)
    at RequestManager.send (/home/ameya/Fresh_install/node_modules/web3/lib/web3/requestmanager.js:61:22)
    at Eth.send [as call] (/home/ameya/Fresh_install/node_modules/web3/lib/web3/method.js:145:58)
    at SolidityFunction.call (/home/ameya/Fresh_install/node_modules/web3/lib/web3/function.js:135:32)
    at Object.<anonymous> (/home/ameya/Fresh_install/voting_main.js:16:32)
    at Module._compile (internal/modules/cjs/loader.js:654:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:665:10)
    at Module.load (internal/modules/cjs/loader.js:566:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:506:12)
    at Function.Module._load (internal/modules/cjs/loader.js:498:3)

这似乎是一个非常简单的例子，它仍然抛出无效的操作码错误。我哪里出错了？

Answer 1

如果您正在使用 .new()，则无需调用 .at()。当您想要与已部署到区 block 链的合约进行交互时，您可以使用 at()。

如果选择部署新合约，应该使用异步版本的方法调用(web3j 1.0不再支持同步)。你的电话应该是这样的:

VotingContract.new(['Rama','Nick','Jose'],{data: byteCode, from: web3.eth.accounts[0], gas: 4700000}, (error, deployedContract) => {
    if (!error) {
        if (deployedContract.address) {
            console.log(deployedContract.totalVotesFor.call('Rama'));
        }
    }
});

请注意回调被触发了两次。第一次是提交交易(deployedContract.transactionHash会被设置)，第二次是在交易被挖出后。

您还可以查看 web3js docs 中的示例(为方便起见粘贴在下面)。

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

let source = fs.readFileSync('nameContract.sol', 'utf8');
let compiledContract = solc.compile(source, 1);
let abi = compiledContract.contracts['nameContract'].interface;
let bytecode = compiledContract.contracts['nameContract'].bytecode;
let gasEstimate = web3.eth.estimateGas({data: bytecode});
let MyContract = web3.eth.contract(JSON.parse(abi));

var myContractReturned = MyContract.new(param1, param2, {
   from:mySenderAddress,
   data:bytecode,
   gas:gasEstimate}, function(err, myContract){
    if(!err) {
       // NOTE: The callback will fire twice!
       // Once the contract has the transactionHash property set and once its deployed on an address.

       // e.g. check tx hash on the first call (transaction send)
       if(!myContract.address) {
           console.log(myContract.transactionHash) // The hash of the transaction, which deploys the contract

       // check address on the second call (contract deployed)
       } else {
           console.log(myContract.address) // the contract address
       }

       // Note that the returned "myContractReturned" === "myContract",
       // so the returned "myContractReturned" object will also get the address set.
    }
  });