Foundry Lottery with proofable randomness

Objective

This is a proofably random smart contract lottery built with foundry. This project is a smart contract lottery using Chainlink VRF to determine a random winner. Chainlink automation is used to call the functions to determine the winner. This project does also include the relevant tests.

1. Users can enter by purchasing a ticket
2. After a specific time period the lottery will draw a winner
3. This will be done with ChainLink Automation (Time based trigger) and VRF (verifiable randomness)
4. The winner will receive all ticket fees gathered.

Tech Stack

• Foundry (Smart Contract Development Framework)
• Chainlink-Brownie-Contracts (Chainlink Smart Contracts)
• Chainlink-VRF (Chainlink´s Verifiable Random Function)
• Chainlink-Automation

Usage

Project Setup

If you want to clone this project run the following command

$ forge init
$ make install

Build and Compile Contracts

$ forge build

Test

$ forge test 

Run test with matching function

$ forge test --match-test <testYourTestName>

Test how much of your contracts your test cover by running this command:

$ forge coverage

get more inforamtion on what functions still need to be tested and output it to coverage.txt

$ forge coverage --report debug > coverage.txt

Debug tool; With this you can navigate throught your contract opcode

$ forge test --debug <testYourTestName>

Gas Estimation

You can estimate how much gas things cost by running:

$ forge snapshot

Anvil (Fooundry Local Dev Chain)

$ anvil

Deploy

$ forge script script/DeployRaffle.s.sol --rpc-url <your_rpc_url> --private-key <your_private_key>

or use the commands in the makefile

deploy to local Anvil chain

here make sure to start up Anvil before running this command

$ make deploy

deploy to Sepolia Testnet

$ make deploy ARGS="--network sepolia"

NOTE FOR DEPLOYMENT

After deploying the contract you must manually register a new Upkeep on Chainlink Automation using the contract address!

Cast

You can interact with your contracts from the command line useing cast

$ cast <subcommand>