- General info
- This code is to create a random smart contract lottery.
- Technologies
- Solidity Language-Foundry Book Forge-Configuration ChainLink Documentation-Dashboard Alchemy-VRF.Chain.Link-Cyfrin Foundry Solidity Course
About.
This code is to create a random smart contract lottery.
- Users can enter by paying for a ticket
- The ticket fees are going to go to the winner during the draw
- After X period of time, the lottery will automatically draw a winner
- and this will be done programmatically
- Using Chainlink VRF & Chainlink Automation
- Chainlink VRF -> Randomness
- Chainlink Automation -> Time based trigger
- Write some deploy scripts
-
- Write out tests
- Work on a local chain
- Forked Testnet
- Forked Mainnet
This is a section of the Cyfrin Foundry Solidity Course.
⭐️ (3:04:09) | Lesson 9: Foundry Smart Contract Lottery
- Foundry Smart Contract Lottery
- Getting Started
- Usage
- Deployment to a testnet or mainnet
- Formatting
- Thank you!
- git
- You'll know you did it right if you can run
git --versionand you see a response likegit version x.x.x
- You'll know you did it right if you can run
- foundry
- You'll know you did it right if you can run
forge --versionand you see a response likeforge 0.2.0 (816e00b 2023-03-16T00:05:26.396218Z)
- You'll know you did it right if you can run
git clone https://github.com/Cyfrin/foundry-smart-contract-lottery-f23
cd foundry-smart-contract-lottery-f23
forge build
If you can't or don't want to run and install locally, you can work with this repo in Gitpod. If you do this, you can skip the clone this repo part.
make anvil
If you're having a hard time installing the chainlink library, you can optionally run this command.
forge install smartcontractkit/chainlink-brownie-contracts@0.6.1 --no-commit
This will default to your local node. You need to have it running in another terminal in order for it to deploy.
make deploy
We talk about 4 test tiers in the video.
- Unit
- Integration
- Forked
- Staging
This repo we cover #1 and #3.
forge test
or
forge test --fork-url $SEPOLIA_RPC_URL
forge coverage
- Setup environment variables
You'll want to set your SEPOLIA_RPC_URL and PRIVATE_KEY as environment variables. You can add them to a .env file, similar to what you see in .env.example.
PRIVATE_KEY: The private key of your account (like from metamask). NOTE: FOR DEVELOPMENT, PLEASE USE A KEY THAT DOESN'T HAVE ANY REAL FUNDS ASSOCIATED WITH IT.- You can learn how to export it here.
SEPOLIA_RPC_URL: This is url of the sepolia testnet node you're working with. You can get setup with one for free from Alchemy
Optionally, add your ETHERSCAN_API_KEY if you want to verify your contract on Etherscan.
- Get testnet ETH
Head over to faucets.chain.link and get some testnet ETH. You should see the ETH show up in your metamask.
- Deploy
make deploy ARGS="--network sepolia"
This will setup a ChainlinkVRF Subscription for you. If you already have one, update it in the scripts/HelperConfig.s.sol file. It will also automatically add your contract as a consumer.
- Register a Chainlink Automation Upkeep
You can follow the documentation if you get lost.
Go to automation.chain.link and register a new upkeep. Choose Custom logic as your trigger mechanism for automation. Your UI will look something like this once completed:
After deploying to a testnet or local net, you can run the scripts.
Using cast deployed locally example:
cast send <RAFFLE_CONTRACT_ADDRESS> "enterRaffle()" --value 0.1ether --private-key <PRIVATE_KEY> --rpc-url $SEPOLIA_RPC_URL
or, to create a ChainlinkVRF Subscription:
make createSubscription ARGS="--network sepolia"
You can estimate how much gas things cost by running:
forge snapshot
And you'll see an output file called .gas-snapshot
To run code formatting:
forge fmt
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