基于Hardhat编写合约测试用例

为智能合约编写自动化测试至关重要，毕竟写智能合约多多少少都会跟用户资金挂钩。

场景

这里假设自己正在开发一个NFT交易平台，这个平台可以让用户售卖自己的NFT，包括ERC721和ERC1155，并且用户可以指定购买者需要支付指定的ERC20 Token购买。
我们先确定自己的测试功能和目标，为了文章篇幅不要太长，我们就以卖家用户调用sell，创建售卖订单功能为目标做测试。

合约代码

我们需要4个合约文件：

1. ERC20
2. ERC721
3. ERC1155
4. NFTSwap（交易平台）

前三种合约最简单的，我们不需要自己再去实现，直接引用Openzeppelin的合约代码即可。
在contracts目录下创建一个新的文件TestDependency.sol，并且把下面的代码粘贴进去

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;

import "@openzeppelin/contracts/token/ERC20/presets/ERC20PresetMinterPauser.sol";
import "@openzeppelin/contracts/token/ERC721/presets/ERC721PresetMinterPauserAutoId.sol";
import "@openzeppelin/contracts/token/ERC1155/presets/ERC1155PresetMinterPauser.sol";

这样需要用到的ERC20，ERC721，ERC1155合约就会被编译到项目中

NFTSwap合约代码我只展示sell相关部分，足够测试即可
在contracts目录下新建一个NFTSwap.sol合约，并粘贴下面的代码

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";

contract NFTSwap is Initializable {
    enum AssetType {
        ERC721,
        ERC1155
    }

    struct Asset {
        address Contract; // NFT Token地址
        uint256 TokenId; // Token id
        uint256 TokenValue; // Token Value, ERC721 为1
        AssetType Type; // NFT 类型
    }

    function __NFTSwap_init() public initializer {}

    function sell(
        Asset[] calldata assets, // 要售卖的NFT，可以同时售卖多个
        address paymentToken, // 指定接受购买支付的 ERC20 代币
        uint256 price // 售卖价格
    ) public virtual returns (uint256 goodsId) {
        // 创建售卖订单逻辑
        //.......
    }

编译合约

➜ npx hardhat compile
Compiled 36 Solidity files successfully

合约编译通过，下一步

引用测试工具包

修改项目根目录下的hardhat.config.js，添加对工具包的引用

require("@nomiclabs/hardhat-waffle");
require('@openzeppelin/hardhat-upgrades');

task("accounts", "Prints the list of accounts", async (taskArgs, hre) => {
  const accounts = await hre.ethers.getSigners();

  for (const account of accounts) {
    console.log(account.address);
  }
});

编写测试代码

这一部分是重点，我会把整个测试脚本文件先拆分讲解，并在文章最后附上完成的代码

引用

在test目录下新建sell-test.js文件，我们将在这里编辑测试用例代码
先添加引用

const { expect, use } = require('chai'); //引入断言库
const { BigNumber } = require('ethers'); // bignumber一会儿要用到
const { deployContract, MockProvider, solidity } = require('ethereum-waffle'); 
const { ethers, upgrades } = require("hardhat");

use(solidity); // 这里是跟 chai 声明使用在solidity合约测试

定义测试套件和全局变量

因为我会在这个套件内定义多个测试用例，模拟多种场景，所以可以定义全局变量，减少代码重复

describe("Test NFTSwap.sell Interface", function () {
    var ERC20; 	// 存放要用到的ERC20
    var ERC721;	// 同上
    var ERC1155; // 同上
    var OWNER; // 这里是为了演示模拟多用户操作 
    var ADDR1; // 同上
}

定义beforeEach

beforeEach会在每个测试用例运行前先运行。可以通过定义beforeEach在每次测试前初始化环境，这样可以做到多个测试用例的数据不会相互影响，因为每次运行用例前，beforeEach都会重置环境

beforeEach(async () => {
    // 模拟不同的两个用户，比如测试完成的买卖流程就应该用 两个用户地址
    [OWNER, ADDR1] = await ethers.getSigners();

    // Owner 用户创建多个合约
    const ERC20PresetMinterPauser = await ethers.getContractFactory("ERC20PresetMinterPauser", OWNER);
    ERC20 = await ERC20PresetMinterPauser.deploy("TestERC20", "T20");

    const ERC721PresetMinterPauserAutoId = await ethers.getContractFactory("ERC721PresetMinterPauserAutoId", OWNER);
    ERC721 = await ERC721PresetMinterPauserAutoId.deploy("TestERC721", "T721", "https://t721.com");

    const ERC1155PresetMinterPauser = await ethers.getContractFactory("ERC1155PresetMinterPauser", OWNER);
    ERC1155 = await ERC1155PresetMinterPauser.deploy("https://t1155.com");

    const NFTSwap = await ethers.getContractFactory("NFTSwap");
    NFT_SWAP = await upgrades.deployProxy(NFTSwap, [], {
        initializer: '__NFTSwap_init'
    });
});

定义测试用例

这里我会定义三个测试用例，模拟售卖不同种类NFT，和同时售卖两种NFT的情况

第一个测试用例

创建售卖1个ERC721 Token订单成功

it("Should be sale an ERC721 token successful", async function () {
    // 确定 NFTSwap合约 部署完成
    await NFT_SWAP.deployed();

    // 确定 ERC721合约 部署完成
    await ERC721.deployed();

    // 增发 id=0 的token，并approve 给 NFTSwap
    var mintERC721Tx = await ERC721.connect(OWNER).mint(OWNER.address);
    await mintERC721Tx.wait();
    var approveERC721Tx = await ERC721.connect(OWNER).setApprovalForAll(NFT_SWAP.address, true);
    await approveERC721Tx.wait();

    // 定义assets, assetType.ERC721 = 1
    var assets = [{ Contract: ERC721.address, TokenId: BigNumber.from(0), TokenValue: BigNumber.from(1), Type: 1 }]

    await ERC20.deployed();
    // 发起交易
    const sellTx = await NFT_SWAP.sell(assets, ERC20.address, BigNumber.from(1000000));
    await sellTx.wait()

    // 获取交易结果
    var receipt = await ethers.provider.getTransactionReceipt(sellTx.hash);
    // 判断交易最终状态，必须为1，1表示合约执行成功
    expect(receipt.status).to.equal(1);
});

第二个测试用例

创建售卖1个ERC1155T oken订单成功

it("Should be sale an ERC1155 token successful", async function () {
    // 确定 NFTSwap合约 部署完成
    await NFT_SWAP.deployed();

    // 确定 ERC1155合约 部署完成
    await ERC1155.deployed();

    // 增发 id=0 的token，并approve 给 NFTSwap
    var mintERC1155Tx = await ERC1155.connect(OWNER).mint(OWNER.address, 1, 10, "0x");
    await mintERC1155Tx.wait();
    var approveERC1155Tx = await ERC1155.connect(OWNER).setApprovalForAll(NFT_SWAP.address, true);
    await approveERC1155Tx.wait();

    // 定义assets, assetType.ERC1155 = 2
    var assets = [{ Contract: ERC1155.address, TokenId: BigNumber.from(1), TokenValue: BigNumber.from(1), Type: 2 }]

    await ERC20.deployed();
    const sellTx = await NFT_SWAP.sell(assets, ERC20.address, BigNumber.from(1000000));
    await sellTx.wait()

    var receipt = await ethers.provider.getTransactionReceipt(sellTx.hash);
    expect(receipt.status).to.equal(1);
});

第三个测试用例

创建售卖 1个ERC721 Token + 1个ERC1155T oken 订单成功

it("Should be packet sale an ERC721 token and an ERC1155 token successful", async function () {
    // 确定 NFTSwap合约 部署完成
    await NFT_SWAP.deployed();

    // 确定 ERC721合约 部署完成
    await ERC721.deployed();

    // 增发 id=0 的ERC721 token，并approve 给 NFTSwap
    var mintERC721Tx = await ERC721.connect(OWNER).mint(OWNER.address);
    await mintERC721Tx.wait();
    var approveERC721Tx = await ERC721.connect(OWNER).setApprovalForAll(NFT_SWAP.address, true);
    await approveERC721Tx.wait();

    // 确定 ERC1155合约 部署完成
    await ERC1155.deployed();

    // 增发 id=0 的ERC1155 token，并approve 给 NFTSwap
    var mintERC1155Tx = await ERC1155.connect(OWNER).mint(OWNER.address, 1, 10, "0x");
    await mintERC1155Tx.wait();
    var approveERC1155Tx = await ERC1155.connect(OWNER).setApprovalForAll(NFT_SWAP.address, true);
    await approveERC1155Tx.wait();

    // 定义assets，这里是用两个 NFT Token的
    var assets = [{ Contract: ERC721.address, TokenId: BigNumber.from(0), TokenValue: BigNumber.from(1), Type: 1 },
    { Contract: ERC1155.address, TokenId: BigNumber.from(1), TokenValue: BigNumber.from(10), Type: 2 }]

    await ERC20.deployed();
    const sellTx = await NFT_SWAP.sell(assets, ERC20.address, BigNumber.from(200000));
    await sellTx.wait()

    var receipt = await ethers.provider.getTransactionReceipt(sellTx.hash);
    expect(receipt.status).to.equal(1);
});

到这里，我们的测试脚本文件已经完成了，接下来直接运行测试脚本，查看测试结果就可以了

运行测试脚本

➜  npx hardhat test test/sell-test.js


  Test NFTSwap.sell Interface
    ✔ Should be sale an ERC721 token successful (120ms)
    ✔ Should be sale an ERC1155 token successful (99ms)
    ✔ Should be packet sale an ERC721 token and an ERC1155 token successful (177ms)


  3 passing (4s)

这里可以看到测试都通过

完整测试脚本代码

const { expect, use } = require('chai');
const { BigNumber } = require('ethers');
const { deployContract, MockProvider, solidity } = require('ethereum-waffle');
const { ethers, upgrades } = require("hardhat");

use(solidity);

describe("Test NFTSwap.sell Interface", function () {
    var ERC20;
    var ERC721;
    var ERC1155;
    var OWNER;
    var ADDR1;
    var NFT_SWAP;

    beforeEach(async () => {
        [OWNER, ADDR1] = await ethers.getSigners();

        const ERC20PresetMinterPauser = await ethers.getContractFactory("ERC20PresetMinterPauser", OWNER);
        ERC20 = await ERC20PresetMinterPauser.deploy("TestERC20", "T20");

        const ERC721PresetMinterPauserAutoId = await ethers.getContractFactory("ERC721PresetMinterPauserAutoId", OWNER);
        ERC721 = await ERC721PresetMinterPauserAutoId.deploy("TestERC721", "T721", "https://t721.com");

        const ERC1155PresetMinterPauser = await ethers.getContractFactory("ERC1155PresetMinterPauser", OWNER);
        ERC1155 = await ERC1155PresetMinterPauser.deploy("https://t1155.com");

        const NFTSwap = await ethers.getContractFactory("NFTSwap");
        NFT_SWAP = await upgrades.deployProxy(NFTSwap, {
            initializer: '__NFTSwap_init'
        });
    });


    it("Should be sale an ERC721 token successful", async function () {
        await NFT_SWAP.deployed();

        await ERC721.deployed();

        var mintERC721Tx = await ERC721.connect(OWNER).mint(OWNER.address);
        await mintERC721Tx.wait();
        var approveERC721Tx = await ERC721.connect(OWNER).setApprovalForAll(NFT_SWAP.address, true);
        await approveERC721Tx.wait();

        var assets = [{ Contract: ERC721.address, TokenId: BigNumber.from(0), TokenValue: BigNumber.from(1), Type: 1 }]

        await ERC20.deployed();

        const sellTx = await NFT_SWAP.sell(assets, ERC20.address, BigNumber.from(1000000));
        await sellTx.wait()

        var receipt = await ethers.provider.getTransactionReceipt(sellTx.hash);
        expect(receipt.status).to.equal(1);
    });

    it("Should be sale an ERC1155 token successful", async function () {
        await NFT_SWAP.deployed();

        await ERC1155.deployed();

        var mintERC1155Tx = await ERC1155.connect(OWNER).mint(OWNER.address, 1, 10, "0x");
        await mintERC1155Tx.wait();
        var approveERC1155Tx = await ERC1155.connect(OWNER).setApprovalForAll(NFT_SWAP.address, true);
        await approveERC1155Tx.wait();

        var assets = [{ Contract: ERC1155.address, TokenId: BigNumber.from(1), TokenValue: BigNumber.from(1), Type: 2 }]

        await ERC20.deployed();
        const sellTx = await NFT_SWAP.sell(assets, ERC20.address, BigNumber.from(1000000));
        await sellTx.wait()

        var receipt = await ethers.provider.getTransactionReceipt(sellTx.hash);
        expect(receipt.status).to.equal(1);
    });

    it("Should be packet sale an ERC721 token and an ERC1155 token successful", async function () {
        await NFT_SWAP.deployed();

        await ERC721.deployed();

        var mintERC721Tx = await ERC721.connect(OWNER).mint(OWNER.address);
        await mintERC721Tx.wait();
        var approveERC721Tx = await ERC721.connect(OWNER).setApprovalForAll(NFT_SWAP.address, true);
        await approveERC721Tx.wait();

        await ERC1155.deployed();

        var mintERC1155Tx = await ERC1155.connect(OWNER).mint(OWNER.address, 1, 10, "0x");
        await mintERC1155Tx.wait();
        var approveERC1155Tx = await ERC1155.connect(OWNER).setApprovalForAll(NFT_SWAP.address, true);
        await approveERC1155Tx.wait();

        var assets = [{ Contract: ERC721.address, TokenId: BigNumber.from(0), TokenValue: BigNumber.from(1), Type: 1 },
        { Contract: ERC1155.address, TokenId: BigNumber.from(1), TokenValue: BigNumber.from(10), Type: 2 }]

        await ERC20.deployed();
        const sellTx = await NFT_SWAP.sell(assets, ERC20.address, BigNumber.from(200000));
        await sellTx.wait()

        var receipt = await ethers.provider.getTransactionReceipt(sellTx.hash);
        expect(receipt.status).to.equal(1);
    });
});

有问题，或者建议请留言，谢谢。