/hardhat-smart-contract-lottery

"Hardhat Smart Contract Lottery" is a blockchain project that leverages Ethereum smart contracts to implement a lottery system. Developed using Hardhat, this project provides a comprehensive setup for Solidity development, testing, and deployment.

Primary LanguageTypeScript

Hardhat Smart Contract Lottery

This Ethereum project provides a decentralized, transparent lottery system built using Solidity and the Hardhat development environment. It leverages Chainlink VRF for secure randomness in winner selection.

Prerequisites

  • Node.js (https://nodejs.org/)
  • Bun (https://bun.sh/)
  • Knowledge of Solidity and smart contract development fundamentals.
  • Experience with Hardhat for development and testing.
  • Understanding of Chainlink VRF for a verifiable source of randomness.

Setup

  1. Clone the Repository:

    git clone https://github.com/nawodyaishan/hardhat-smart-contract-lottery.git
cd hardhat-smart-contract-lottery

  2. Install Dependencies:

    bun install

  3. Environment Variables:

    • Create a .env file in the project root (not tracked by version control).
    • Use this file to store:
      • API Keys: Etherscan, Infura, CoinMarketCap.
      • Network RPC URLs (Sepolia, Mainnet, etc.).
      • Private keys or mnemonic phrases for testing and deployment.

Core Smart Contracts

  • Raffle.sol

    • Entry management (purchase tickets).
    • Chainlink VRF integration to obtain provably random numbers.
    • Automated winner selection logic.
    • Distribution of the prize pool to the winner.

  • VRFCoordinatorV2Mock.sol

    • Implements essential VRF functionality for local development and testing.

Essential Hardhat Tasks

  • bun run compile: Compiles smart contracts.
  • bun run test: Executes the test suite.
  • bun run deploy:contracts: Deploys to the specified network.
  • bun run verify: Verifies contracts on Etherscan (use --network networkName).

Development Workflow

  1. Modify Contracts: Update Solidity contracts in the contracts/ directory.
  2. Write Tests: Write comprehensive tests in the test/ directory using Mocha/Chai.
  3. Local Testing:
    • bun run deploy:contracts --network hardhat
    • Interact with the contracts, and check test results.
  4. Testnet Deployment:
    • Configure target testnet in hardhat.config.ts
    • Obtain testnet ETH via faucets.
    • Deploy using bun run deploy:contracts --network <targetNetwork>
  5. Verification: Verify contracts on Etherscan using bun run verify.