Lottery 🎲

Smart contract lottery using ChainLink VRF2 for generating a truly random number. This random number is used to choose a Lottery Winner. Most testing was done on a local HardHat network and then on goerli testnet. For testing on goerli, you have to create a subscription at https://vrf.chain.link/goerli and register a new keeper https://automation.chain.link/goerli You need to get some testnet ETH and Link(>13) here https://faucets.chain.link/goerli for goerli testnet.

📁 Table of Contents

• General Info
• Technologies Used
• Requirements For Initial Setup
• Setup
• Contact

🚩 General Information

• Anyone can enter the lottery by sending at minimum 0.001 ETH to the contract
• Every 30 seconds a verrifiably random winner will be picked using randomness from Chainlink VRFv2 Coordinator

💻 Technologies Used

• Chainlink VRFv2
• Hardhat
• Ethers
• Mocha, Chai testing framework

👀 Requirements For Initial Setup

• Install NodeJS, should work with any node version below 18.13.0

📟 Setup

1. 💾 Clone/Download the Repository

2. 📦 Install Dependencies:

$ git clone https://github.com/Dmitry1007/smart-contract-lottery.git
$ cd smart-contract-lottery
$ yarn install

3. 🔍 .env environment variables required to set up

Create .env file inside project folder

• You can get your ethereum or testnet API key from Alchemy or any other Node as a service operator
• You can get your private key from your wallet (Don't share your private keys EVER), best to have a separate wallet just for testing
• ChainLink VRF Subscription can be obtained here
• Key Hash and address of vrf coordinator can be obtained from here here
• You can get your etherscan API -key here.

GOERLI_RPC_API="Goerli API key"
PRIVATE_KEY="Private key of your wallet you want to deploy contracts from"
ETHERSCAN_API_KEY="Etherscan API key in order to verify your contracts"
COINMARKETCAP_API_KEY="Get a gas report file after deploying"

4. ⚠️ Run Unit tests on local HardHat network or Mega staging test on GOERLI Testnet

$ yarn hardhat test

$ yarn hardhat coverage

$ yarn hardhat test --network goerli

5. 🚀 Deploy to HardHat local network or GOERLI

$ yarn hardhat deploy

$ yarn hardhat deploy --network goerli

Note:

utils/verify.js implements the verification script on Etherscan, you don't need to do anything else.

💬 Contact

feel free to contact me with any questions.