web3-testing

# Web3 Smart Contract Testing

Master comprehensive testing strategies for smart contracts using Hardhat, Foundry, and advanced testing patterns.

## When to Use This Skill

- Writing unit tests for smart contracts
- Setting up integration test suites
- Performing gas optimization testing
- Fuzzing for edge cases
- Forking mainnet for realistic testing
- Automating test coverage reporting
- Verifying contracts on Etherscan

## Hardhat Testing Setup

```javascript
// hardhat.config.js
require("@nomicfoundation/hardhat-toolbox");
require("@nomiclabs/hardhat-etherscan");
require("hardhat-gas-reporter");
require("solidity-coverage");

module.exports = {
  solidity: {
    version: "0.8.19",
    settings: {
      optimizer: {
        enabled: true,
        runs: 200
      }
    }
  },
  networks: {
    hardhat: {
      forking: {
        url: process.env.MAINNET_RPC_URL,
        blockNumber: 15000000
      }
    },
    goerli: {
      url: process.env.GOERLI_RPC_URL,
      accounts: [process.env.PRIVATE_KEY]
    }
  },
  gasReporter: {
    enabled: true,
    currency: 'USD',
    coinmarketcap: process.env.COINMARKETCAP_API_KEY
  },
  etherscan: {
    apiKey: process.env.ETHERSCAN_API_KEY
  }
};
```

## Unit Testing Patterns

```javascript
const { expect } = require("chai");
const { ethers } = require("hardhat");
const { loadFixture, time } = require("@nomicfoundation/hardhat-network-helpers");

describe("Token Contract", function () {
  // Fixture for test setup
  async function deployTokenFixture() {
    const [owner, addr1, addr2] = await ethers.getSigners();

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

    return { token, owner, addr1, addr2 };
  }

  describe("Deployment", function () {
    it("Should set the right owner", async function () {
      const { token, owner } = await loadFixture(deployTokenFixture);
      expect(await token.owner()).to.equal(owner.address);
    });

    it("Should assign total supply