Hardhat testing setup in Blockchain / Solidity - Mini Project: Build & Apply

Hardhat Testing Setup

📖 Scenario: You are building a simple smart contract project using Hardhat. To make sure your contract works correctly, you want to write tests. This project will guide you step-by-step to set up the testing environment in Hardhat.

🎯 Goal: Set up a Hardhat project with a basic test file that checks if the contract deploys successfully.

📋 What You'll Learn

Create a Hardhat project with npm init -y and install hardhat

Create a sample contract file

Write a test file using Mocha and Chai

Run the test and see the output

💡 Why This Matters

🌍 Real World

Testing smart contracts before deploying them to a blockchain helps catch bugs early and saves money.

💼 Career

Blockchain developers must write and run tests to ensure their contracts work correctly and securely.

1

Initialize Hardhat Project

Run npm init -y to create a package.json file and then install Hardhat by running npm install --save-dev hardhat. After that, create a Hardhat project by running npx hardhat and choose create a basic sample project. This will create the initial project files including hardhat.config.js.

Blockchain / Solidity

# Run the commands in your terminal to initialize the project
# Your code here

Need a hint?

Use your terminal to run the commands exactly as shown to set up the Hardhat project.

2

Create a Sample Contract

Delete the default contracts/Lock.sol and test/Lock.js files. Create a new file called contracts/SimpleStorage.sol with this exact Solidity code:

pragma solidity ^0.8.0;

contract SimpleStorage {
    uint256 public storedData;

    function set(uint256 x) public {
        storedData = x;
    }

    function get() public view returns (uint256) {
        return storedData;
    }
}

Blockchain / Solidity

# Create the file contracts/SimpleStorage.sol
# Paste the Solidity code for SimpleStorage contract
# Your code here

Need a hint?

Make sure the contract file is saved exactly as contracts/SimpleStorage.sol with the given code.

3

Write a Test for the Contract

Create a test file called test/sample-test.js with this exact JavaScript code:

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

describe("SimpleStorage", function () {
  it("Should deploy and set value correctly", async function () {
    const SimpleStorage = await ethers.getContractFactory("SimpleStorage");
    const simpleStorage = await SimpleStorage.deploy();
    await simpleStorage.deployed();

    await simpleStorage.set(42);
    expect(await simpleStorage.get()).to.equal(42);
  });
});

Blockchain / Solidity

# Create the file test/sample-test.js
# Paste the JavaScript test code for SimpleStorage
# Your code here

Need a hint?

Make sure the test file is saved exactly as test/sample-test.js with the given code.

4

Run the Test and See the Output

Run the test by executing npx hardhat test in your terminal. You should see output that shows the test passed with a message like 1 passing.

Blockchain / Solidity

# Run the test command in your terminal
# Your code here

Need a hint?

Use your terminal to run npx hardhat test and look for the message 1 passing to confirm the test passed.