javascript - 类型错误 : Cannot read properties of undefined (reading 'getContractFactory' ) when testing contract

Question

如果不是很清楚，第一个问题就这么简单，但我会尽力而为。

我目前正在浏览 youtube 视频，以测试我与安全帽、以太币和华夫饼 (https://www.youtube.com/watch?v=oTpmNEYV8iQ&list=PLw-9a9yL-pt3sEhicr6gmuOQdcmWXhCx4&index=6) 的契约(Contract)。

这是契约(Contract):

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.9;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";

contract MyContract is ERC721 {

  constructor(string memory name, string memory symbol) 
    ERC721(name, symbol) {

    }
  
}

这里是 test.js:

const { expect } = require('chai');

describe("MyContract", function() {
  
  it("should return correct name", async function() {
    const MyContract = hre.ethers.getContractFactory("MyContract");
    const myContractDeployed = await MyContract.deploy("MyContractName", "MCN");
    await myContractDeployed.deployed();
    
    expect(await myContractDeployed.name()).to.equal("MyContractName");
  });
});

当我在终端中运行“npx hardhat test”时，它返回:

MyContract
    1) should return correct name


  0 passing (7ms)
  1 failing

  1) MyContract
       should return correct name:
     TypeError: Cannot read properties of undefined (reading 'getContractFactory')
      at Context.<anonymous> (test\test.js:7:35)
      at processImmediate (node:internal/timers:464:21)

我的代码与视频中的代码相匹配，但我很难理解为什么会出现 TypeError。非常感谢任何指导!

编辑:

我以某种方式修复了它，我不明白它究竟是如何修复它的，但确实如此。而不仅仅是安装

npm install @nomiclabs/hardhat-waffle ethereum-waffle chai @nomiclabs/hardhat-ethers ethers

我安装了

npm install --save-dev @nomiclabs/hardhat-waffle ethereum-waffle chai @nomiclabs/hardhat-ethers ethers

然后终端打印出来

npm WARN idealTree Removing dependencies.@nomiclabs/hardhat-waffle in favor of devDependencies.@nomiclabs/hardhat-waffle
npm WARN idealTree Removing dependencies.ethereum-waffle in favor of devDependencies.ethereum-waffle
npm WARN idealTree Removing dependencies.@nomiclabs/hardhat-ethers in favor of devDependencies.@nomiclabs/hardhat-ethers
npm WARN idealTree Removing dependencies.ethers in favor of devDependencies.ethers

然后我删除了 ethers.getContractFactory("MyContract") 前面的 hre，它起作用了!如果有人想解释为什么这可能会解决它，我很乐意阅读它，否则我将继续前进。

Answer 1

在您的 hardhat.config.js 文件顶部添加以下代码片段

require("@nomiclabs/hardhat-waffle");