Hardhat以太坊智能合约开发框架基础教程

Chain哥
更新于 2022-12-21 19:12
阅读 3773

### 一、Hardhat框架介绍
        Hardhat是一个基于javascript和solidity的开发框架。可实现编译、部署、测试、开源和调试以太坊应用的开发环境。Hardhat是一个围绕任务和插件的概念设计的;Hardhat 的大部分功能来自插件。
### 二、Hardhat框架优点
        1、Hardhat 拥有大量插件，并允许自定义、灵活性和可扩展性。

2、Hardhat运行同时使用ether.js和web3.js。

3、Hardhat有良好的 console.log() 调试能力；会在调试时提供代码中发生的堆栈跟踪。

4、Hardhat 提供原生Typescript支持，并且还有一个Vscode扩展，为 Vscode 编辑器添加了可靠的支持。

5、Hardhat 带有一个内置的本地以太坊网络，称为Hardhat Network，用于在本地机器上运行和部署智能合约，是一个专为开发而设计的本地以太坊网络节点。

### 三、哪些项目在使用Hardhat
        Chainlink ；Uniswap；Aave ；SushiSwap ； ENS 等主流项目。
### 四、Hardhat环境搭建
        1、请安装node.js 12.x及以上的版本

2、Hardhat先安装到本地。
        
```
npm install --save-dev hardhat
```
     3、先创建一个空文件夹执行安装命令;通过执行 npx hardhat 创建项目。
     npx hardhat
     
![image.png](https://img.learnblockchain.cn/attachments/2022/12/SV3EHYPV63a2e8ac22cd0.png)

![image.png](https://img.learnblockchain.cn/attachments/2022/12/JMMMU4eH63a2e8be30439.png)
### 五、创建编译合约
        1、在contracts目录下编写一个合约文件 Token.js       
        
```
// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

library SafeMath {

function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

return c;
    }

function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;

return c;
    }

function mul(uint256 a, uint256 b) internal pure returns (uint256) {

if (a == 0) {
            return 0;
        }

uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

return c;
    }

function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

return c;
    }

function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0, "SafeMath: modulo by zero");
        return a % b;
    }
}
interface IERC20 {

function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

abstract contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;
    constructor (string memory tokenName, string memory tokenSymbol, uint8 tokenDecimals)  {
        _name = tokenName;
        _symbol = tokenSymbol;
        _decimals = tokenDecimals;
    }
    function name() public view returns (string memory) {
        return _name;
    }
    function symbol() public view returns (string memory) {
        return _symbol;
    }
    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

contract ERC20 is IERC20 {
    using SafeMath for uint256;

mapping (address => uint256) private _balances;

mapping (address => mapping (address => uint256)) private _allowances;

uint256 private _totalSupply;
    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }
    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }
    function transfer(address recipient, uint256 amount) public returns (bool) {
        _transfer(msg.sender, recipient, amount);
        return true;
    }
    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowances[owner][spender];
    }
    function approve(address spender, uint256 value) public returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }
    function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount));
        return true;
    }
    function _transfer(address sender, address recipient, uint256 amount) internal {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

_balances[sender] = _balances[sender].sub(amount);
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }
    function _mint(address account, uint256 amount) internal {
        require(account != address(0), "ERC20: mint to the zero address");

_totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }
    function _burn(address account, uint256 value) internal {
        require(account != address(0), "ERC20: burn from the zero address");

_totalSupply = _totalSupply.sub(value);
        _balances[account] = _balances[account].sub(value);
        emit Transfer(account, address(0), value);
    }
    function _approve(address owner, address spender, uint256 value) internal {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

_allowances[owner][spender] = value;
        emit Approval(owner, spender, value);
    }
    function _burnFrom(address account, uint256 amount) internal {
        _burn(account, amount);
        _approve(account, msg.sender, _allowances[account][msg.sender].sub(amount));
    }
}
contract ERC20Template is ERC20, ERC20Detailed {
    constructor() ERC20Detailed("USDT", "USDT", 18) {
        _mint(msg.sender, 10000000000 * (10 ** uint256(decimals())));
    }
}

```
        
2、编译合约执行 npx hardhat compile      
        
```
 % npx hardhat compile

Compiled 1 Solidity file successfully
```
        
3、在test目录下 编写测试案例 Token.js

```
//Chai，这是一个断言库
const { expect } = require("chai");

describe("创建合约测试案例", function() {
  it("CreateContract", async function() {
    //ethers.js中的Signer 代表以太坊账户对象。 它用于将交易发送到合约和其他帐户。
    // 在这里，我们获得了所连接节点中的帐户列表，在本例中节点为Hardhat Network，并且仅保留第一个帐户
    const [owner, addr1, addr2] = await ethers.getSigners();
    //ethers.js中的ContractFactory是用于部署新智能合约的抽象，因此此处的Token是用来实例代币合约的工厂。
    const Token = await ethers.getContractFactory("ERC20Template");
    //在ContractFactory上调用deploy()将启动部署，并返回解析为Contract的Promise。 该对象包含了智能合约所有函数的方法。
    const hardhatToken = await Token.deploy();
    //当你调用deploy()时，将发送交易，但是直到该交易打包出块后，合约才真正部署。 调用deployed()将返回一个Promise，因此该代码将阻塞直到部署完成。
    await hardhatToken.deployed();
    //查询代币总量
    const balance = await hardhatToken.balanceOf(await owner.getAddress());
    console.log("代币总量="+balance)
    // 给钱包addr1转移100代币数量
    await hardhatToken.transfer(await addr1.getAddress(), 100);
    //查询地址addr1余额
    const balanceAddr1 = await hardhatToken.balanceOf(await addr1.getAddress());
    console.log("地址addr1余额="+balanceAddr1)
    // 钱包addr1给钱包addr2转移100代币数量
    await hardhatToken.connect(addr1).transfer(await addr2.getAddress(), 100);
    const balanceAddr11 = await hardhatToken.balanceOf(await addr1.getAddress());
    console.log("余额转移给addr2后地址addr1余额="+balanceAddr11)
    //查询地址addr2余额
    const balanceAddr2 = await hardhatToken.balanceOf(await addr2.getAddress());
    console.log("地址addr2余额="+balanceAddr2)
    //断言判断
    expect(await hardhatToken.balanceOf(await addr2.getAddress())).to.equal(100);
  });
});

```
执行 npx hardhat test 查看运行结果：

![image.png](https://img.learnblockchain.cn/attachments/2022/12/CZN0wv0o63a2e9242911e.png)
### 六、部署合约到正式网络网络
       1、hardhat.config.js 在此文件里面配置 网络信息
       
```
require("@nomicfoundation/hardhat-toolbox");
require("@nomiclabs/hardhat-etherscan");

module.exports = {
  networks: {
    bsc: {
      url: `https://bsc-dataseed1.ninicoin.io/`,
      accounts: [`部署合约钱包私钥`],
    },
    bscTest: {
      url: `https://data-seed-prebsc-2-s3.binance.org:8545/`,
      accounts: [`部署合约钱包私钥`]
    },
    hecoTest: {
      url: 'https://http-testnet.hecochain.com',
      accounts: [`部署合约钱包私钥`]
    }
  },
  etherscan: {
    apiKey: {
      bsc: '',
      hecoTestnet: '',
    }
  },
  solidity: "0.8.9"
};

```
2、在scripts目录下创建 TokenDeploy.js 文件

```
async function main() {
  const [deployer] = await ethers.getSigners();
  console.log("获取部署钱包地址:",await deployer.getAddress());
  console.log("获取部署钱包地址余额:", (await deployer.getBalance()).toString());
  //指定合约工程要部署的名称
  const Token = await ethers.getContractFactory("ERC20Template");
  const token = await Token.deploy();
  await token.deployed();

console.log("部署后合约地址:", token.address);
}

main()
    .then(() => process.exit(0))
    .catch(error => {
      console.error(error);
      process.exit(1);
    });

```
执行部署命令：npx hardhat run scripts/TokenDeploy.js --network hecoTest

```
 % npx hardhat run scripts/TokenDeploy.js --network hecoTest

获取部署钱包地址: 0xc290436b3da897115493a1547B52783c50f0Bef3
获取部署钱包地址余额: 1138718537000000000
部署后合约地址: 0x9AdAaDb89C6968CF6C4Ef116C614EAedD314a6EE
```
### 七、合约源代码开源
        注：需要申请浏览器 apiKey配置在 hardhat.config.js文件此处。
 HECO测试浏览器查看验证
 
![image.png](https://img.learnblockchain.cn/attachments/2022/12/nr4nZNZ563a2e97a42677.png)

![image.png](https://img.learnblockchain.cn/attachments/2022/12/QXGLpbGH63a2e9930a4af.png)
 开源执行命令，成功后就可以在浏览器上查看了。 
 
```
% npx hardhat verify 0x9adaadb89c6968cf6c4ef116c614eaedd314a6ee --network hecoTest

```

![image.png](https://img.learnblockchain.cn/attachments/2022/12/Ih7t8s2Z63a2e9c46a9fd.png)
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一、Hardhat框架介绍

Hardhat是一个基于javascript和solidity的开发框架。可实现编译、部署、测试、开源和调试以太坊应用的开发环境。Hardhat是一个围绕任务和插件的概念设计的;Hardhat 的大部分功能来自插件。

二、Hardhat框架优点

1、Hardhat 拥有大量插件，并允许自定义、灵活性和可扩展性。

2、Hardhat运行同时使用ether.js和web3.js。

3、Hardhat有良好的 console.log() 调试能力；会在调试时提供代码中发生的堆栈跟踪。

4、Hardhat 提供原生Typescript支持，并且还有一个Vscode扩展，为 Vscode 编辑器添加了可靠的支持。

5、Hardhat 带有一个内置的本地以太坊网络，称为Hardhat Network，用于在本地机器上运行和部署智能合约，是一个专为开发而设计的本地以太坊网络节点。

三、哪些项目在使用Hardhat

Chainlink ；Uniswap；Aave ；SushiSwap ； ENS 等主流项目。

四、Hardhat环境搭建

1、请安装node.js 12.x及以上的版本

2、Hardhat先安装到本地。

npm install --save-dev hardhat

 3、先创建一个空文件夹执行安装命令;通过执行 npx hardhat 创建项目。
 npx hardhat

五、创建编译合约

1、在contracts目录下编写一个合约文件 Token.js

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

library SafeMath {

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b &lt;= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;

        return c;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {

        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0, "SafeMath: modulo by zero");
        return a % b;
    }
}
interface IERC20 {

    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

abstract contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;
    constructor (string memory tokenName, string memory tokenSymbol, uint8 tokenDecimals)  {
        _name = tokenName;
        _symbol = tokenSymbol;
        _decimals = tokenDecimals;
    }
    function name() public view returns (string memory) {
        return _name;
    }
    function symbol() public view returns (string memory) {
        return _symbol;
    }
    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

contract ERC20 is IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;
    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }
    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }
    function transfer(address recipient, uint256 amount) public returns (bool) {
        _transfer(msg.sender, recipient, amount);
        return true;
    }
    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowances[owner][spender];
    }
    function approve(address spender, uint256 value) public returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }
    function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount));
        return true;
    }
    function _transfer(address sender, address recipient, uint256 amount) internal {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _balances[sender] = _balances[sender].sub(amount);
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }
    function _mint(address account, uint256 amount) internal {
        require(account != address(0), "ERC20: mint to the zero address");

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }
    function _burn(address account, uint256 value) internal {
        require(account != address(0), "ERC20: burn from the zero address");

        _totalSupply = _totalSupply.sub(value);
        _balances[account] = _balances[account].sub(value);
        emit Transfer(account, address(0), value);
    }
    function _approve(address owner, address spender, uint256 value) internal {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = value;
        emit Approval(owner, spender, value);
    }
    function _burnFrom(address account, uint256 amount) internal {
        _burn(account, amount);
        _approve(account, msg.sender, _allowances[account][msg.sender].sub(amount));
    }
}
contract ERC20Template is ERC20, ERC20Detailed {
    constructor() ERC20Detailed("USDT", "USDT", 18) {
        _mint(msg.sender, 10000000000 * (10 ** uint256(decimals())));
    }
}

2、编译合约执行 npx hardhat compile

 % npx hardhat compile

Compiled 1 Solidity file successfully

3、在test目录下编写测试案例 Token.js

//Chai，这是一个断言库
const { expect } = require("chai");

describe("创建合约测试案例", function() {
  it("CreateContract", async function() {
    //ethers.js中的Signer 代表以太坊账户对象。 它用于将交易发送到合约和其他帐户。
    // 在这里，我们获得了所连接节点中的帐户列表，在本例中节点为Hardhat Network，并且仅保留第一个帐户
    const [owner, addr1, addr2] = await ethers.getSigners();
    //ethers.js中的ContractFactory是用于部署新智能合约的抽象，因此此处的Token是用来实例代币合约的工厂。
    const Token = await ethers.getContractFactory("ERC20Template");
    //在ContractFactory上调用deploy()将启动部署，并返回解析为Contract的Promise。 该对象包含了智能合约所有函数的方法。
    const hardhatToken = await Token.deploy();
    //当你调用deploy()时，将发送交易，但是直到该交易打包出块后，合约才真正部署。 调用deployed()将返回一个Promise，因此该代码将阻塞直到部署完成。
    await hardhatToken.deployed();
    //查询代币总量
    const balance = await hardhatToken.balanceOf(await owner.getAddress());
    console.log("代币总量="+balance)
    // 给钱包addr1转移100代币数量
    await hardhatToken.transfer(await addr1.getAddress(), 100);
    //查询地址addr1余额
    const balanceAddr1 = await hardhatToken.balanceOf(await addr1.getAddress());
    console.log("地址addr1余额="+balanceAddr1)
    // 钱包addr1给钱包addr2转移100代币数量
    await hardhatToken.connect(addr1).transfer(await addr2.getAddress(), 100);
    const balanceAddr11 = await hardhatToken.balanceOf(await addr1.getAddress());
    console.log("余额转移给addr2后地址addr1余额="+balanceAddr11)
    //查询地址addr2余额
    const balanceAddr2 = await hardhatToken.balanceOf(await addr2.getAddress());
    console.log("地址addr2余额="+balanceAddr2)
    //断言判断
    expect(await hardhatToken.balanceOf(await addr2.getAddress())).to.equal(100);
  });
});

执行 npx hardhat test 查看运行结果：

六、部署合约到正式网络网络

1、hardhat.config.js 在此文件里面配置网络信息

require("@nomicfoundation/hardhat-toolbox");
require("@nomiclabs/hardhat-etherscan");

module.exports = {
  networks: {
    bsc: {
      url: `https://bsc-dataseed1.ninicoin.io/`,
      accounts: [`部署合约钱包私钥`],
    },
    bscTest: {
      url: `https://data-seed-prebsc-2-s3.binance.org:8545/`,
      accounts: [`部署合约钱包私钥`]
    },
    hecoTest: {
      url: 'https://http-testnet.hecochain.com',
      accounts: [`部署合约钱包私钥`]
    }
  },
  etherscan: {
    apiKey: {
      bsc: '',
      hecoTestnet: '',
    }
  },
  solidity: "0.8.9"
};

2、在scripts目录下创建 TokenDeploy.js 文件

async function main() {
  const [deployer] = await ethers.getSigners();
  console.log("获取部署钱包地址:",await deployer.getAddress());
  console.log("获取部署钱包地址余额:", (await deployer.getBalance()).toString());
  //指定合约工程要部署的名称
  const Token = await ethers.getContractFactory("ERC20Template");
  const token = await Token.deploy();
  await token.deployed();

  console.log("部署后合约地址:", token.address);
}

main()
    .then(() => process.exit(0))
    .catch(error => {
      console.error(error);
      process.exit(1);
    });

执行部署命令：npx hardhat run scripts/TokenDeploy.js --network hecoTest

 % npx hardhat run scripts/TokenDeploy.js --network hecoTest

获取部署钱包地址: 0xc290436b3da897115493a1547B52783c50f0Bef3
获取部署钱包地址余额: 1138718537000000000
部署后合约地址: 0x9AdAaDb89C6968CF6C4Ef116C614EAedD314a6EE

七、合约源代码开源

注：需要申请浏览器 apiKey配置在 hardhat.config.js文件此处。 HECO测试浏览器查看验证

开源执行命令，成功后就可以在浏览器上查看了。

% npx hardhat verify 0x9adaadb89c6968cf6c4ef116c614eaedd314a6ee --network hecoTest

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