Solidity Lottery

This project demonstrates a basic lottery use case implemented with Solidity. Now with foundry ✅

Features

• Allow users to buy lottery tickets by sending ether to the contract.
• Once a certain number of tickets have been sold, the contract should pick a random winner and transfer the prize money to them.
• The contract should prevent users from buying more tickets than the maximum allowed.
• The contract should prevent users from buying tickets after the lottery has closed.
• The contract should allow the contract owner to set the maximum number of tickets allowed and the prize amount.
• A mechanism that allows an external app to live display the status of the lottery (by pushing events for instance)

Upgrades

• Better randomness using Chainlink VRF
• Allow users to buy multiple tickets at the same time
• fallback / receive functions

How to use

• After deploying the contract (with a price in ETH for each ticket and a max number of tickets), the lottery is labeled as Initialized, the owner can start the lottery by calling the startLottery function. It will confirm parameters and allow users to buy tickets.
• Each ticket can be bought separately by using the buyTicket function. It will transfer the price of the ticket to the contract and emit an event.
• Once the last ticket is bought, the lottery is labeled as Ended and the winner is automatically picked. The total pool prize is then transferred to the winner.
• The owner can call the resetLottery function to reset the lottery and start a new one using the same contract, using a new ticket price and a new max number of tickets.

Local tests (Foundry)

Deployment

1. Source the env file with the needed vars
2. Run anvil to start the local blockchain environment
3. Create a deployer account with cast wallet import deployer --interactive and file in the private key of an already funded account.
4. Run forge create ./src/Lottery.sol:Lottery --rpc-url $RPC_URL --account deployer --constructor-args $WEI_TICKET_PRICE --constructor-args $MAX_TICKET_NB

The contract is now deployed ! 🚀