Fork 网络

本质是创建目标网络的分叉链，注意这不会拉取所有数据，而是要用到什么数据就拉取哪部分数据。

完成这个事情共2步骤:

• 节点配置
• 代码应用
• 执行

节点配置

在 hardhat.config.js 配置

networks: {
  hardhat: {
    forking: {
      url: "https://mainnet.infura.io/v3/<key>",
    }
  }
}

默认情况下将从最近的主网区块中分叉。但是我们建议从特定的块号进行分叉（防止出现奇奇怪怪的结果）。

networks: {
  hardhat: {
    forking: {
      url: "https://mainnet.infura.io/v3/<key>",
      blockNumber: 14390000
    }
  }
}

或者通过命令行启动节点

npx hardhat node --fork https://goerli.infura.io/v3/<key>

输出

Started HTTP and WebSocket JSON-RPC server at http://127.0.0.1:8545/

Accounts
========

WARNING: These accounts, and their private keys, are publicly known.
Any funds sent to them on Mainnet or any other live network WILL BE LOST.

Account #0: 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 (10000 ETH)
Private Key: 0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80

Account #1: 0x70997970C51812dc3A010C7d01b50e0d17dc79C8 (10000 ETH)
Private Key: 0x59c6995e998f97a5a0044966f0945389dc9e86dae88c7a8412f4603b6b78690d

Account #2: 0x3C44CdDdB6a900fa2b585dd299e03d12FA4293BC (10000 ETH)
Private Key: 0x5de4111afa1a4b94908f83103eb1f1706367c2e68ca870fc3fb9a804cdab365a

Account #3: 0x90F79bf6EB2c4f870365E785982E1f101E93b906 (10000 ETH)
Private Key: 0x7c852118294e51e653712a81e05800f419141751be58f605c371e15141b007a6

Account #4: 0x15d34AAf54267DB7D7c367839AAf71A00a2C6A65 (10000 ETH)
Private Key: 0x47e179ec197488593b187f80a00eb0da91f1b9d0b13f8733639f19c30a34926a

Account #5: 0x9965507D1a55bcC2695C58ba16FB37d819B0A4dc (10000 ETH)
Private Key: 0x8b3a350cf5c34c9194ca85829a2df0ec3153be0318b5e2d3348e872092edffba

Account #6: 0x976EA74026E726554dB657fA54763abd0C3a0aa9 (10000 ETH)
Private Key: 0x92db14e403b83dfe3df233f83dfa3a0d7096f21ca9b0d6d6b8d88b2b4ec1564e

Account #7: 0x14dC79964da2C08b23698B3D3cc7Ca32193d9955 (10000 ETH)
Private Key: 0x4bbbf85ce3377467afe5d46f804f221813b2bb87f24d81f60f1fcdbf7cbf4356

Account #8: 0x23618e81E3f5cdF7f54C3d65f7FBc0aBf5B21E8f (10000 ETH)
Private Key: 0xdbda1821b80551c9d65939329250298aa3472ba22feea921c0cf5d620ea67b97

Account #9: 0xa0Ee7A142d267C1f36714E4a8F75612F20a79720 (10000 ETH)
Private Key: 0x2a871d0798f97d79848a013d4936a73bf4cc922c825d33c1cf7073dff6d409c6

Account #10: 0xBcd4042DE499D14e55001CcbB24a551F3b954096 (10000 ETH)
Private Key: 0xf214f2b2cd398c806f84e317254e0f0b801d0643303237d97a22a48e01628897

Account #11: 0x71bE63f3384f5fb98995898A86B02Fb2426c5788 (10000 ETH)
Private Key: 0x701b615bbdfb9de65240bc28bd21bbc0d996645a3dd57e7b12bc2bdf6f192c82

Account #12: 0xFABB0ac9d68B0B445fB7357272Ff202C5651694a (10000 ETH)
Private Key: 0xa267530f49f8280200edf313ee7af6b827f2a8bce2897751d06a843f644967b1

Account #13: 0x1CBd3b2770909D4e10f157cABC84C7264073C9Ec (10000 ETH)
Private Key: 0x47c99abed3324a2707c28affff1267e45918ec8c3f20b8aa892e8b065d2942dd

Account #14: 0xdF3e18d64BC6A983f673Ab319CCaE4f1a57C7097 (10000 ETH)
Private Key: 0xc526ee95bf44d8fc405a158bb884d9d1238d99f0612e9f33d006bb0789009aaa

Account #15: 0xcd3B766CCDd6AE721141F452C550Ca635964ce71 (10000 ETH)
Private Key: 0x8166f546bab6da521a8369cab06c5d2b9e46670292d85c875ee9ec20e84ffb61

Account #16: 0x2546BcD3c84621e976D8185a91A922aE77ECEc30 (10000 ETH)
Private Key: 0xea6c44ac03bff858b476bba40716402b03e41b8e97e276d1baec7c37d42484a0

Account #17: 0xbDA5747bFD65F08deb54cb465eB87D40e51B197E (10000 ETH)
Private Key: 0x689af8efa8c651a91ad287602527f3af2fe9f6501a7ac4b061667b5a93e037fd

Account #18: 0xdD2FD4581271e230360230F9337D5c0430Bf44C0 (10000 ETH)
Private Key: 0xde9be858da4a475276426320d5e9262ecfc3ba460bfac56360bfa6c4c28b4ee0

Account #19: 0x8626f6940E2eb28930eFb4CeF49B2d1F2C9C1199 (10000 ETH)
Private Key: 0xdf57089febbacf7ba0bc227dafbffa9fc08a93fdc68e1e42411a14efcf23656e

WARNING: These accounts, and their private keys, are publicly known.
Any funds sent to them on Mainnet or any other live network WILL BE LOST.

代码应用

本教程通过模拟账户来演示代码应用

Hardhat Network 允许您模拟任何地址。即使您无权访问其私钥，这也可以让您从该帐户发送交易。

下面是根据在 hardhat.config.js 配置 fork 后的代码示例:

合约部分

pragma solidity ^0.8.9;

contract Fork {
    address immutable public owner;

    constructor() {
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(msg.sender == owner, "Only the owner can call this function.");
        _;
    }

    function test(uint a, uint b) public onlyOwner view returns(uint) {
        return a+b;
    }
}
`

作者已在 `goerli` 部署该合约，地址: 
```bash
0x1BC902734C51711301aee8D78a37CdAbF4123c57

脚本部分 scripts/fork.js

const { ethers } = require("hardhat");

async function transfer() {
    const [sender] = await ethers.getSigners();
    const recipientAddress = "0x05421c943Db220a71531fD76E0267813a15cAB05"; 
    const amount = BigInt("1000000000000000000");
    const tx = await sender.sendTransaction({
        to: recipientAddress,
        value: amount,
    });
    await tx.wait();
    console.log("转账完成！");
}

(async () => {
    // 冒充所有者地址
  await hre.network.provider.request({
    method: "hardhat_impersonateAccount",
    params: ["0x05421c943Db220a71531fD76E0267813a15cAB05"]
  });

  // 让签名者冒充所有者地址
  const ownerSigner = await ethers.getSigner("0x05421c943Db220a71531fD76E0267813a15cAB05");

  // 获取部署的合约实例
  const contractAddress = "0x1BC902734C51711301aee8D78a37CdAbF4123c57";
  
  // 作者账户余额不足才需要这样，如果你够的话可以不用管这步骤
  await transfer()

  const Fork = await ethers.getContractFactory("Fork");
  const fork = await Fork.attach(contractAddress);

  // 使用所有者签名者连接到已部署的合约
  const connectedContract = fork.connect(ownerSigner);

  // 函数调用
  const result = await connectedContract.test(1, 21111);

  console.log('执行成功！')
})()

执行

npx hardhat run .\scripts\fork.js --network hardhat

输出

转账完成！
执行成功！