contract Counter {    uint counter;
    function Counter() public {        counter = 0;    }    function count() public {        counter = counter + 1;    }}

// Specifies the version of Solidity, using semantic versioning.// 了解更多：https://solidity.readthedocs.io/en/v0.5.10/layout-of-source-files.html#pragmapragma solidity ^0.8.0;
// 定义合约名称 `HelloWorld`。// 一个合约是函数和数据（其状态）的集合。// 一旦部署，合约就会留在以太坊区块链的一个特定地址上。// 了解更多： https://solidity.readthedocs.io/en/v0.5.10/structure-of-a-contract.htmlcontract HelloWorld {
    // 定义`string`类型变量 `message`    // 状态变量是其值永久存储在合约存储中的变量。    // 关键字 `public` 使得可以从合约外部访问。    // 并创建了一个其它合约或客户端可以调用访问该值的函数。    string public message;
    // 类似于很多基于类的面向对象语言，    // 构造函数是仅在合约创建时执行的特殊函数。    // 构造器用于初始化合约的数据。    // 了解更多：https://solidity.readthedocs.io/en/v0.5.10/contracts.html#constructors    constructor(string memory initMessage) public {        // 接受一个字符变量 `initMessage`        // 并为合约的存储变量`message` 赋值        message = initMessage;    }
    // 一个 public 函数接受字符参数并更新存储变量 `message`    function update(string memory newMessage) public {        message = newMessage;    }}

## Install node version managercurl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.3/install.sh | bash## Hardhat支持的node最低版本是16.0nvm install v18.12.1nvm use v18.12.1node -v

mkdir demo & cd demo## Install the Hardhat dependenciesnpm install --save-dev hardhat## initialize the projectsnpx hardhat

$ npx hardhatYou are using a version of Node.js that is not supported by Hardhat, and it may work incorrectly, or not work at all.
Please, make sure you are using a supported version of Node.js.
To learn more about which versions of Node.js are supported go to https://hardhat.org/nodejs-versions888    888                      888 888               888888    888                      888 888               888888    888                      888 888               8888888888888  8888b.  888d888 .d88888 88888b.   8888b.  888888888    888     "88b 888P"  d88" 888 888 "88b     "88b 888888    888 .d888888 888    888  888 888  888 .d888888 888888    888 888  888 888    Y88b 888 888  888 888  888 Y88b.888    888 "Y888888 888     "Y88888 888  888 "Y888888  "Y888
👷 Welcome to Hardhat v2.12.7 👷‍
? What do you want to do? …❯ Create a JavaScript project  Create a TypeScript project  Create an empty hardhat.config.js  Quit

| - demo| -- contracts // 存放.sol合约代码| -- node_modules | -- scripts // 存放合约部署脚本| -- test // 存放单元测试代码| -- .gitignore| -- hardhat.config.ts // hardhat框架的配置文件| -- package.json| -- tsconfig.json

// SPDX-License-Identifier: GPL-3.0pragma solidity >=0.8.2 <0.9.0;
/** * @title Escrow * @dev Store & retrieve value in a variable */contract Escrow {    /// @dev Emitted when `value` is deposited for `payee`.    event Deposited(address indexed payee, uint256 weiAmount);    /// @dev Emitted when `value` is withdrawn from `payee`.    event Withdrawn(address indexed payee, uint256 weiAmount);
    /// @dev The owner of the contract.    address private _owner;    /// @dev Mapping of address to deposits.    mapping(address => uint256) private _deposits;
    /**     * @dev Initializes the contract setting the deployer as the initial owner.     */    constructor() {        _owner = msg.sender;    }
    /**     * @dev Stores the sent amount as credit to be withdrawn.     *     * Emits a {Deposited} event.     */    function deposit() public payable virtual {        uint256 amount = msg.value;        _deposits[msg.sender] += amount;
        // emit the event        emit Deposited(msg.sender, amount);    }
    /**     * @dev Withdraw accumulated balance for a payee, forwarding all gas to the     * recipient.     *     * WARNING: Forwarding all gas opens the door to reentrancy vulnerabilities.     * Make sure you trust the recipient, or are either following the     * checks-effects-interactions pattern or using {ReentrancyGuard}.     *     * Emits a {Withdrawn} event.     */    function withdraw() public virtual {        address payee = msg.sender;        uint256 amount = _deposits[payee];
        // check if the balance is enough to send the payment        require(amount > 0, "Address: insufficient balance");
        // set the balance to 0 before sending the payment        _deposits[payee] = 0;
        (bool success, ) = payee.call{value: amount}("");        require(success, "Address: unable to send value, may have reverted");
        // emit the event        emit Withdrawn(payee, amount);    }
    /**     * @dev Returns the address of the current owner.     */    function owner() public view virtual returns (address) {        return _owner;    }
    /**     * @dev Returns the amount of wei owned by an address.     */    function balance() public view virtual returns (uint256) {        return _deposits[msg.sender];    }}

$ npx hardhat compileGenerating typings for: 1 artifacts in dir: typechain-types for target: ethers-v5Successfully generated 6 typings!Compiled 1 Solidity file successfully

import { loadFixture } from "@nomicfoundation/hardhat-network-helpers";import { expect } from "chai";import { ethers } from "hardhat";
describe("Escrow", 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 deployFixture() {    // Contracts are deployed using the first signer/account by default    const [owner, payee] = await ethers.getSigners();
    const Escrow = await ethers.getContractFactory("Escrow");    const escrow = await Escrow.deploy();
    return { escrow, owner, payee };  }
  describe("Deployment", function () {    it("Should set the right owner", async function () {      const { escrow, owner } = await loadFixture(deployFixture);
      expect(await escrow.owner()).to.equal(owner.address);    });  });
  describe("Deposit", function () {    it("Should deposit funds ok", async function () {      const { escrow, payee } = await loadFixture(deployFixture);
      await expect(escrow.connect(payee).deposit({ value: 100 }))      .to.be.ok      .to.emit(escrow, "Deposited")      .withArgs(payee.address, 100)      .to.changeEtherBalances([escrow, payee], [100, -100]);    });  });
  describe("Withdrawals", function () {    it("Should withdraw funds ok", async function () {      const { escrow, payee } = await loadFixture(deployFixture);
      await expect(escrow.connect(payee).deposit({ value: 100 }))      .to.be.ok      .to.emit(escrow, "Deposited")      .withArgs(payee.address, 100)      .to.changeEtherBalances([escrow, payee], [100, -100]);
      await expect(escrow.connect(payee).withdraw())      .to.be.ok      .to.emit(escrow, "Withdrawn")      .withArgs(payee.address, 100)      .to.changeEtherBalances([escrow, payee], [-100, 100]);    });
    it("Should fail if insufficient balance", async function () {      const { escrow, payee } = await loadFixture(deployFixture);
      await expect(escrow.connect(payee).deposit({ value: 100 }))      .to.be.ok      .to.emit(escrow, "Deposited")      .withArgs(payee.address, 100)      .to.changeEtherBalances([escrow, payee], [100, -100]);
      await expect(escrow.connect(payee).withdraw())      .to.be.ok
      await expect(escrow.connect(payee).withdraw())      .to.be.revertedWith("Address: insufficient balance")    });  });});

import { HardhatUserConfig } from "hardhat/config";import "@nomicfoundation/hardhat-toolbox";
const config: HardhatUserConfig = {  solidity: "0.8.17",  networks: {    goerli: {      // Go to https://www.alchemyapi.io, sign up, create      url: 'https://eth-goerli.g.alchemy.com/v2/{alchemy_api_key}',      // Replace this private key with your Goerli 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      accounts: [        '{account_private_key}',      ],      gas: 5000000,      gasPrice: 70000000000,    },  }};
export default config;

import { ethers } from "hardhat";
async function main() {  const Escrow = await ethers.getContractFactory('Escrow')  const escrow = await Escrow.deploy()
  console.log(`Escrow deployed to Goerili. Address: ${escrow.address}`)}
// We recommend this pattern to be able to use async/await everywhere// and properly handle errors.main().catch((error) => {  console.error(error);  process.exitCode = 1;});

$ npx hardhat run --network goerli scripts/deploy.tsEscrow deployed to Goerili. Address: 0x7B36f017429681ccE27f28D968E570eF7bE2Cc0f