fcc-hardhat-smartcontract-lottery

Lesson 9 of 32 hours course about Web3 fullstack by freecodecamp

Index

• Getting Started
  • Requirements
  • Quickstart
    • Clone from Github
    • Install dependencies
• Useage
  • Deploy
  • Testing
    • Test Coverage
• Deployment to a testnet or mainnet
  • Estimate gas cost in EUR
  • Verify on etherscan

Getting started

Requirements

• git
  • You'll know if you have git installed by running the command git --version on your terminal and see a response like git version x.x.x
• Nodejs
  • You'll know if you have Node.js installed by running the command node --version or node -v on your terminal and see a response like vx.x.x
• Npm
  • It should be installed with Node.js

Quickstart

Clone from Github

 git clone https://github.com/Pasq04/fcc-hardhat-smartcontract-lottery
 cd fcc-hardhat-smartcontract-lottery

Install dependencies

 npm i --save-dev

Usage

Deploy

  npx hardhat deploy

Testing

  npx hardhat test

Test Coverage

  npx hardhat coverage

Deploying to a testnet or a mainnet

1. Setup environment variables

   You'll set your RINKEBY_RPC_URL and your PRIVATE_KEY as environment variables. You have to create a new .env file and put them into this file like below:

     RINKEBY_RPC_URL = "value"
     PRIVATE_KEY = "value"

• What is the RINKEBY_RPC_URL and how you can get it

  The RINKEBY_RPC_URL is the URL of the Rinkeby testnet node you're going to work with during your tests, you can get it for free from Alchemy

• What is the PRIVATE_KEY and how you can get it

  The PRIVATE_KEY is 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.

2. Get Testnet ETH

   Head over to faucets.chain.link and get some tesnet ETH & LINK. You should see the ETH and LINK show up in your metamask.

3. Setup a Chainlink VRF Subscription ID

   Head over to vrf.chain.link and setup a new subscription, and get a subscriptionId. You can reuse an old subscription if you already have one.

   In your helper-hardhat-config.js add your subscriptionId under the section of the chainId you're using. If you're deploying to rinkeby, add your subscriptionId in the subscriptionId field under the 4 section.

   Then run:

     npx hardhat deploy --network rinkeby

   And copy / remember the contract address.

4. Add your contract address as a Chainlink VRF Consumer

   Go back to vrf.chain.link and under your subscription add Add consumer and add your contract address. You should also fund the contract with a minimum of 1 LINK.

5. Register a Chainlink Keepers Upkeep

   You can follow the documentation if you get lost.

   Go to keepers.chain.link and register a new upkeep.

6. Enter your Raffle! Enter the lottery by running:

     npx hardhat run scripts/enter.js --network rinkeby

Estimate gas cost in EUR

Verify on Etherscan