Basic Smart Contract

This project demonstrates a simple Ethereum smart contract for storing and retrieving a numerical value on the blockchain. It covers essential smart contract concepts such as state variables, functions, and blockchain interaction, making it an ideal starting point for Solidity development.

What is a Smart Contract?

A smart contract is a self-executing program that runs on a blockchain. It:

• Contains code (functions) and data (state).
• Executes automatically when conditions are met.
• Cannot be modified once deployed (immutable).
• Runs decentralized on the blockchain.

Hardhat Overview

Hardhat is a development environment to compile, deploy, test, and debug your Ethereum software. It helps developers manage and automate recurring tasks while remaining extensible for advanced use cases.

Key Features:

• Flexible and Extensible: Customize and extend functionality with plugins.
• Built-in Network: Comes with Hardhat Network for local testing.
• Comprehensive Debugging: Provides advanced debugging and error reporting tools.

Running a Local Ethereum Network

You can start a local Ethereum network using Hardhat by running:

npx hardhat node

What Happens?

• A local Ethereum blockchain is launched for testing.
• Multiple accounts are automatically created.
• Each account is pre-funded with test ETH.
• Private keys for these accounts are displayed, allowing interaction via scripts or wallets.

Why is this useful?

• Test smart contracts without real ETH.
• Simulate multiple users (e.g., owner, buyer, seller).
• Run transactions locally before deploying to a live network.

⚠️ Never use these private keys on a real network.

Deploying the Smart Contract

To deploy the contract to the local Hardhat network, run:

npx hardhat run scripts/deploy.ts --network localhost

What Happens?

• The smart contract is compiled and deployed to the local blockchain.
• A contract address is generated.
• You can interact with the contract using this address.

Interacting with the Smart Contract

Open Hardhat Console

npx hardhat console --network localhost

Load the Contract

const contract = await ethers.getContractAt(
  "BasicStorage",
  "<DEPLOYED_CONTRACT_ADDRESS>"
);

Replace <DEPLOYED_CONTRACT_ADDRESS> with your actual contract address from deployment.

Read the Stored Value

await contract.getNumber();

Update the Stored Value

await contract.setNumber(99);

Verify the Change

await contract.getNumber();

It should now return 99.

Running Tests

To ensure the smart contract works correctly, you can run automated tests using Hardhat.

Running the Tests

Run the following command:

npx hardhat test

What These Tests Do

• ✅ First Test: Ensures the contract is deployed with the correct initial value.
• ✅ Second Test: Verifies that setNumber() correctly updates the stored value.

If successful, the output should show:

BasicStorage
  ✔ Should deploy the contract with an initial value
  ✔ Should update the stored number

2 passing (1s)

These tests help confirm that the contract behaves as expected before deploying to a live network.

Continuous Integration (CI/CD) for Testing

This project includes GitHub Actions workflows for automated testing:

1. Automated Tests on Push & PR (ci.yml)

• Runs tests automatically when you push changes to main or dev.
• Ensures that any updates do not break existing functionality.
• Tests are executed using Node.js 22 in a GitHub Actions workflow.

2. Manual Test Execution (ci-manual.yml)

• Allows manually running tests from the GitHub Actions UI.
• Useful for verifying changes before pushing them.

How to Trigger Manual Tests?

1. Go to the GitHub Actions tab.
2. Select Run Hardhat Tests (Manual).
3. Click Run workflow.

This ensures that smart contracts are thoroughly tested before deployment.