Smart Contract Lottery

This project is part of the Cyfrin Updraft Foundry Fundamentals course, demonstrating the implementation of a decentralized lottery system using Solidity and Foundry.

Overview

A decentralized lottery system where participants can enter by paying an entrance fee. The lottery is managed by a smart contract that randomly selects a winner and transfers the accumulated prize pool to them.

Technologies Used

• Foundry: A blazing fast, portable, and modular toolkit for Ethereum application development
  • Forge: Testing framework
  • Cast: Command-line tool for interacting with EVM smart contracts
  • Anvil: Local Ethereum node
• Solidity: Smart contract programming language
• Chainlink: For price feeds and VRF (Verifiable Random Function)
• Solmate: For efficient and secure smart contract implementations

Project Structure

├── src/                    # Source files containing smart contracts
├── test/                   # Test files for smart contracts
├── script/                 # Deployment and interaction scripts
├── lib/                    # External dependencies
│   ├── chainlink-brownie-contracts/  # Chainlink contracts
│   └── solmate/           # Solmate contracts
├── documentation/         # Project documentation
├── broadcast/            # Deployment transaction data
├── cache/               # Foundry cache
├── out/                 # Compiled contracts
├── .github/             # GitHub configuration
├── foundry.toml         # Foundry configuration
└── Makefile            # Build automation

Getting Started

Prerequisites

• Foundry
• Git

Installation

1. Clone the repository:

git clone <repository-url>
cd foundry-smart-contract-lottery

2. Install dependencies:

forge install

Building

forge build

Testing

forge test

Deployment

1. Set up your environment variables in .env:

PRIVATE_KEY=your_private_key
RPC_URL=your_rpc_url

2. Deploy the contract:

forge script script/DeployLottery.s.sol:DeployLotteryScript --rpc-url $RPC_URL --private-key $PRIVATE_KEY --broadcast

Features

• Decentralized lottery system
• Chainlink VRF for secure random number generation
• Price feed integration for ETH/USD conversion
• Automated winner selection
• Prize pool management

Testing

The project includes comprehensive tests covering:

• Contract deployment
• Lottery entry functionality
• Winner selection
• Prize distribution
• Edge cases and error conditions

Run the tests with:

forge test

License

This project is part of the Cyfrin Updraft Foundry Fundamentals course.