Hardhat 环境搭建及教程示例

一.安装node.js

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash
nvm install 18
nvm use 18
nvm alias default 18
npm install npm --global # Upgrade npm to the latest version

二. 安装hardhat

2.1 创建hardhat安装目录

mkdir hardhat
cd hardhat

2.2 安装hardhat

npm install --save-dev hardhat
ls
# 安装后的目录
# node_modules      package-lock.json package.json

2.3 在安装hardhat的目录下运行hardhat

npx hardhat

选择创建hardhat配置文件

 2.4 hardhat架构

Hardhat是围绕**task(任务)和plugins(插件)**的概念设计的。 **Hardhat **的大部分功能来自插件，作为开发人员，你可以自由选择你要使用的插件。

2.5 Task(任务)

每次你从CLI运行Hardhat时，你都在运行任务。 例如 npx hardhat compile正在运行compile任务。 要查看项目中当前可用的任务，运行npx hardhat。 通过运行npx hardhat help [task]，可以探索任何任务。

2.6 Plugins(插件)

Hardhat 不限制选择哪种工具，但是它确实内置了一些插件，所有这些也都可以覆盖。 大多数时候，使用给定工具的方法是将其集成到Hardhat中作为插件。

在本教程中，我们将使用hardhat-toolbox插件。 通过他们与以太坊进行交互并测试合约。 稍后将解释它们的用法。 要安装它们，请在项目目录中运行：

npm install --save-dev @nomicfoundation/hardhat-toolbox

在hardhar.config.js文件中添加下面的代码

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

/** @type import('hardhat/config').HardhatUserConfig */
module.exports = {
  solidity: "0.8.18",
};

三. 编写、编译、测试、调试智能合约

3.1 写一个简单的智能合约

在hardhat目录下创建一个新的目录

mkdir contracts
cd contracts

添加Token.sol智能合约

//SPDX-License-Identifier: UNLICENSED

// Solidity files have to start with this pragma.
// It will be used by the Solidity compiler to validate its version.
pragma solidity ^0.8.9;


// This is the main building block for smart contracts.
contract Token {
    // Some string type variables to identify the token.
    string public name = "My Hardhat Token";
    string public symbol = "MHT";

    // The fixed amount of tokens, stored in an unsigned integer type variable.
    uint256 public totalSupply = 1000000;

    // An address type variable is used to store ethereum accounts.
    address public owner;

    // A mapping is a key/value map. Here we store each account's balance.
    mapping(address => uint256) balances;

    // The Transfer event helps off-chain applications understand
    // what happens within your contract.
    event Transfer(address indexed _from, address indexed _to, uint256 _value);

    /**
     * Contract initialization.
     */
    constructor() {
        // The totalSupply is assigned to the transaction sender, which is the
        // account that is deploying the contract.
        balances[msg.sender] = totalSupply;
        owner = msg.sender;
    }

    /**
     * A function to transfer tokens.
     *
     * The `external` modifier makes a function *only* callable from *outside*
     * the contract.
     */
    function transfer(address to, uint256 amount) external {
        // Check if the transaction sender has enough tokens.
        // If `require`'s first argument evaluates to `false` then the
        // transaction will revert.
        require(balances[msg.sender] >= amount, "Not enough tokens");

        // Transfer the amount.
        balances[msg.sender] -= amount;
        balances[to] += amount;

        // Notify off-chain applications of the transfer.
        emit Transfer(msg.sender, to, amount);
    }

    /**
     * Read only function to retrieve the token balance of a given account.
     *
     * The `view` modifier indicates that it doesn't modify the contract's
     * state, which allows us to call it without executing a transaction.
     */
    function balanceOf(address account) external view returns (uint256) {
        return balances[account];
    }
}

3.2 编译

npx hardhat compile

3.3 测试 

创建test文件夹，创建测试文件Token.js

mkdir test
cd test

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

describe("Token contract", function () {
  it("Deployment should assign the total supply of tokens to the owner", async function () {
    const [owner] = await ethers.getSigners();

    const Token = await ethers.getContractFactory("Token");

    const hardhatToken = await Token.deploy();

    const ownerBalance = await hardhatToken.balanceOf(owner.address);
    expect(await hardhatToken.totalSupply()).to.equal(ownerBalance);
  });
});

运行test命令

npx hardhat test

 

 

3.4 调试智能合约

Hardhat内置了Hardhat Network ，这是一个专为开发而设计的以太坊网络。 它允许你部署合约，运行测试和调试代码。 这是Hardhat所连接的默认网络，因此你无需进行任何设置即可工作。 你只需运行测试就好。

Solidity 中使用 console.log
在Hardhat Network上运行合约和测试时，你可以在Solidity代码中调用console.log()打印日志信息和合约变量。 你必须先从合约代码中导入**Hardhat **的console.log再使用它。

修改只能合约

pragma solidity ^0.8.9;

import "hardhat/console.sol";

contract Token {
  //...
}

function transfer(address to, uint256 amount) external {
    require(balances[msg.sender] >= amount, "Not enough tokens");

    console.log(
        "Transferring from %s to %s %s tokens",
        msg.sender,
        to,
        amount
    );

    balances[msg.sender] -= amount;
    balances[to] += amount;

    emit Transfer(msg.sender, to, amount);
}

修改测试文件

// This is an example test file. Hardhat will run every *.js file in `test/`,
// so feel free to add new ones.

// Hardhat tests are normally written with Mocha and Chai.

// We import Chai to use its asserting functions here.
const { expect } = require("chai");

// We use `loadFixture` to share common setups (or fixtures) between tests.
// Using this simplifies your tests and makes them run faster, by taking
// advantage of Hardhat Network's snapshot functionality.
const { loadFixture } = require("@nomicfoundation/hardhat-network-helpers");

// `describe` is a Mocha function that allows you to organize your tests.
// Having your tests organized makes debugging them easier. All Mocha
// functions are available in the global scope.
//
// `describe` receives the name of a section of your test suite, and a
// callback. The callback must define the tests of that section. This callback
// can't be an async function.
describe("Token contract", function () {
  // We define a fixture to reuse the same setup in every test. We use
  // loadFixture to run this setup once, snapshot that state, and reset Hardhat
  // Network to that snapshot in every test.
  async function deployTokenFixture() {
    // Get the ContractFactory and Signers here.
    const Token = await ethers.getContractFactory("Token");
    const [owner, addr1, addr2] = await ethers.getSigners();

    // To deploy our contract, we just have to call Token.deploy() and await
    // its deployed() method, which happens once its transaction has been
    // mined.
    const hardhatToken = await Token.deploy();

    await hardhatToken.deployed();

    // Fixtures can return anything you consider useful for your tests
    return { Token, hardhatToken, owner, addr1, addr2 };
  }

  // You can nest describe calls to create subsections.
  describe("Deployment", function () {
    // `it` is another Mocha function. This is the one you use to define each
    // of your tests. It receives the test name, and a callback function.
    //
    // If the callback function is async, Mocha will `await` it.
    it("Should set the right owner", async function () {
      // We use loadFixture to setup our environment, and then assert that
      // things went well
      const { hardhatToken, owner } = await loadFixture(deployTokenFixture);

      // `expect` receives a value and wraps it in an assertion object. These
      // objects have a lot of utility methods to assert values.

      // This test expects the owner variable stored in the contract to be
      // equal to our Signer's owner.
      expect(await hardhatToken.owner()).to.equal(owner.address);
    });

    it("Should assign the total supply of tokens to the owner", async function () {
      const { hardhatToken, owner } = await loadFixture(deployTokenFixture);
      const ownerBalance = await hardhatToken.balanceOf(owner.address);
      expect(await hardhatToken.totalSupply()).to.equal(ownerBalance);
    });
  });

  describe("Transactions", function () {
    it("Should transfer tokens between accounts", async function () {
      const { hardhatToken, owner, addr1, addr2 } = await loadFixture(
        deployTokenFixture
      );
      // Transfer 50 tokens from owner to addr1
      await expect(
        hardhatToken.transfer(addr1.address, 50)
      ).to.changeTokenBalances(hardhatToken, [owner, addr1], [-50, 50]);

      // Transfer 50 tokens from addr1 to addr2
      // We use .connect(signer) to send a transaction from another account
      await expect(
        hardhatToken.connect(addr1).transfer(addr2.address, 50)
      ).to.changeTokenBalances(hardhatToken, [addr1, addr2], [-50, 50]);
    });

    it("Should emit Transfer events", async function () {
      const { hardhatToken, owner, addr1, addr2 } = await loadFixture(
        deployTokenFixture
      );

      // Transfer 50 tokens from owner to addr1
      await expect(hardhatToken.transfer(addr1.address, 50))
        .to.emit(hardhatToken, "Transfer")
        .withArgs(owner.address, addr1.address, 50);

      // Transfer 50 tokens from addr1 to addr2
      // We use .connect(signer) to send a transaction from another account
      await expect(hardhatToken.connect(addr1).transfer(addr2.address, 50))
        .to.emit(hardhatToken, "Transfer")
        .withArgs(addr1.address, addr2.address, 50);
    });

    it("Should fail if sender doesn't have enough tokens", async function () {
      const { hardhatToken, owner, addr1 } = await loadFixture(
        deployTokenFixture
      );
      const initialOwnerBalance = await hardhatToken.balanceOf(owner.address);

      // Try to send 1 token from addr1 (0 tokens) to owner.
      // `require` will evaluate false and revert the transaction.
      await expect(
        hardhatToken.connect(addr1).transfer(owner.address, 1)
      ).to.be.revertedWith("Not enough tokens");

      // Owner balance shouldn't have changed.
      expect(await hardhatToken.balanceOf(owner.address)).to.equal(
        initialOwnerBalance
      );
    });
  });
});

运行测试

npx hardhat test

 看到输出了log

四. 部署合约到网络

4.1 创建scripts文件夹，添加deploy.js文件

async function main() {
  const [deployer] = await ethers.getSigners();

  console.log("Deploying contracts with the account:", deployer.address);

  console.log("Account balance:", (await deployer.getBalance()).toString());

  const Token = await ethers.getContractFactory("Token");
  const token = await Token.deploy();

  console.log("Token address:", token.address);
}

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

4.2 发布到hardhat自己的网络实例

npx hardhat run scripts/deploy.js

Deploying contracts with the account: 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266
Account balance: 10000000000000000000000
Token address: 0x5FbDB2315678afecb367f032d93F642f64180aa3

4.3 发布到Ganache网络

修改配置文件hardhat.config.js

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

/** @type import('hardhat/config').HardhatUserConfig */
module.exports = {
  solidity: "0.8.18",
  networks: {
    deployment: {
      url: `http://127.0.0.1:7545`,
      accounts: ["bc549ba74b85bf9cc89309fc094cd868ff39215570b64271e19be9c1977df279"]
    }
  }
};

npx hardhat run scripts/deploy.js --network deployment

Deploying contracts with the account: 0xEb110D13835ff1e9B65320682601634D041dD505
Account balance: 98996267410475486878
Token address: 0x3f4f9B074bfd9B0C4920FD28b374e2B8E7B618f4

 看到Ganache已经有记录

4.4 发布到sepolia测试网

修改配置文件hardhat.config.js

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

// Go to https://infura.io, sign up, create a new API key
// in its dashboard, and replace "KEY" with it
const INFURA_API_KEY = "KEY";

// Replace this private key with your Sepolia account private key
// To export your private key from Metamask, open Metamask and
// go to Account Details > Export Private Key
// Beware: NEVER put real Ether into testing accounts
const SEPOLIA_PRIVATE_KEY = "YOUR SEPOLIA PRIVATE KEY";

module.exports = {
  solidity: "0.8.9",
  networks: {
    sepolia: {
      url: `https://sepolia.infura.io/v3/${INFURA_API_KEY}`,
      accounts: [SEPOLIA_PRIVATE_KEY]
    }
  }
};

npx hardhat run scripts/deploy.js --network sepolia

这个我没有试，有兴趣的可以试一下

参考文档：

hardhat官网教程

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