Simple Lottery

Simple Lottery is a decentralized take on reddit's /r/millionairemakers. A player can purchase a lottery ticket with a "one ticket per address" limitation. When all the tickets are sold, the winning number is drawn via Chainlink VRF. The total prize pool is then automatically fowarded to the winner.

My Ethereum address

0x9d3aDec7fb41447f1e744Fd3e73520AEf19Cc551

Live

Visit https://blockchain-developer-bootcamp-final-project-6a69w4aq1-xoddong.vercel.app/

Screencast

Part 1: https://www.loom.com/share/3b79fe9ffc3d41c584a06154014ee0b6?sharedAppSource=personal_library Part 2: https://www.loom.com/share/1c8917da1b78474aad2ff444369f7622?sharedAppSource=personal_library

Quickstart

Requirements

• nodejs
  • Expected version "^12.0.0 || ^14.0.0 || >=16.0.0"
• NPM or YARN

Installation

git clone https://github.com/xoddong/blockchain-developer-bootcamp-final-project
cd blockchain-developer-bootcamp-final-project

# install
yarn install

If you see the following error, please try running yarn install with nvm

error hardhat@2.7.0: The engine "node" is incompatible with this module.

Compile

yarn compile

Hardhat produces an artifacts directory for all the contrat builds. This project has configured the artifacts directory path to be "./client/src/artifacts" via hardhat.config.ts

Deploy

yarn deploy:kovan

When deploying the contracts, please utilize the yarn commands. The yarn commands add the flag --export-all to produce a mapping of all the contracts. The frontend utilizes these files to get the deployed contract address

Test

yarn test

Running the test will:

1. Deploy the contracts that match the fixture

await deployments.fixture(["lottery"]); // deploys files that have the matching tag: "lottery"

2. Runs the test

Deploy to Kovan

To deploy to a testnet or a live network, you need the following environment variables:

1. KOVAN_RPC_URL=https://eth-ropsten.alchemyapi.io/v2/
2. PRIVATE_KEY=0xabc123abc123abc123abc123abc123abc123abc123abc123abc123abc123abc1

Your KOVAN_RPC_URL is the URL of your blockchain node, for example, from alchemy.

Your MNEMONIC is the mnemonic phrases of your MetaMask.

You can set them in a file named .env. Please make sure you do not commit this file.

You'll also need testnet ETH and testnet LINK. You can find both here.

Once you do so, you can run:

yarn deploy:kovan

Fund your contract with LINK.

npx hardhat fund-link --contract insert-contract-address-here --network kovan

And purchase a lottery ticket

npx hardhat run scripts/purchaseTicket.ts --network kovan

Client

You can interact with the deployed contract on Kovan in our client app. To start the app:

cd client
yarn install
yarn start

To deploy your own instance to work with in local client, first compile and redeploy a new contract.

yarn compile
yarn deploy:kovan
npx hardhat fund-link --contract {NEW_CONTRACT_ADDRESS} --network kovan

cd client
yarn install
yarn start