MaxListenersExceededWarning：检测到可能的 EventEmitter 内存泄漏

Question

我正在尝试为我的 Solidity 合约开发一些测试。我这里有一个 compile.js 脚本：

const path = require('path');
const solc = require('solc');
const fs = require('fs-extra');

const buildPath = path.resolve(__dirname, 'build');
fs.removeSync(buildPath);

const campaignPath = path.resolve(__dirname, 'contracts', 'Campaign.sol');
const source = fs.readFileSync(campaignPath, 'utf-8');
const output = solc.compile(source, 1).contracts;

fs.ensureDirSync(buildPath);

for (let contract in output) {
  fs.outputJsonSync(
    path.resolve(buildPath, contract.replace(':', '') + '.json'),
    output[contract]
  );
}

这个 EventEmitter 内存泄漏的罪魁祸首可能是这段代码中的某个地方吗？我以前从未运行遇到过这个错误。当我运行我的第一次测试时出现错误，这是我的测试文件：

const assert = require('assert');
const ganache = require('ganache-cli');
const Web3 = require('web3');
const web3 = new Web3(ganache.provider());

const compiledFactory = require('../ethereum/build/CampaignFactory.json');
const compiledCampaign = require('../ethereum/build/Campaign.json');

let accounts;
let factory;
let campaignAddress;
let campaign;

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

  factory = await new web3.eth.Contract(JSON.parse(compiledFactory.interface))
    .deploy({ data: compiledFactory.bytecode })
    .send({ from: accounts[0], gas: '1000000' });

  await factory.methods.createCampaign('100').send({
    from: accounts[0],
    gas: '1000000'
  });

  [campaignAddress] = await factory.methods.getDeployedCampaigns().call();
  campaign = new web3.eth.Contract(
    JSON.parse(compiledCampaign.interface),
    campaignAddress
  );
});

describe('Campaigns', () => {
  it('deploys a factory and a campaign', () => {
    assert.ok(factory.options.address);
    assert.ok(campaign.options.address);
  });
});

在这个 EventEmitter 内存泄漏之后我得到的第二个错误是说我的 getDeployedCampaigns() 不是一个函数，但如果你在这里查看 Campaign.sol 文件，它显然是：

pragma solidity ^0.4.17;

contract CampaignFactory {
    address[] public deployedCampaigns;

    function createCampaign(uint minimum) public {
      address newCampaign = new Campaign(minimum, msg.sender);

      deployedCampaigns.push(newCampaign);
    }

    function getDeployedCampaigns() public view returns (address[]) {
        return deployedCampaigns;
    }
}

Answer 1

我认为这是由内存泄漏引起的：web3.eth.Contract()

它有一个已知的内存泄漏。我目前正在处理类似的问题。

https://github.com/ChainSafe/web3.js/issues/3042

MaxListenersExceededWarning：检测到可能的 EventEmitter 内存泄漏

MaxListenersExceededWarning: Possible EventEmitter memory leak detected

mocha.js

node.js

solidity