Lesson 9: Hardhat Smart Contract Lottery

Lesson 9 from the Web3, Full Stack Solidity, Smart Contract & Blockchain - Beginner to Expert ULTIMATE Course | Javascript Edition: https://github.com/smartcontractkit/full-blockchain-solidity-course-js#lesson-9-hardhat-smart-contract-lottery

Official code at: https://github.com/PatrickAlphaC/hardhat-smartcontract-lottery-fcc

Notes

• using the Automation* interfaces provided by Chainlink as opposed to Keepers* (which seems legacy)
  • https://docs.chain.link/chainlink-automation
• in order to register a new Upkeep for the sample Remix app using a Custom trigger
• replaced

  vrfCoordinatorV2Mock = await ethers.getContract("VRFCoordinatorV2Mock", deployer)

  (and similar) with

  const vrfCoordinatorV2MockDeployment = await deployments.get("VRFCoordinatorV2Mock")
  vrfCoordinatorV2Mock = await ethers.getContractAt(
      vrfCoordinatorV2MockDeployment.abi,
      vrfCoordinatorV2MockDeployment.address
  )

• replaced transactionReceipt.events with transactionReceipt.logs
• replaced

  await expect(raffle.enterRaffle()).to.be.revertedWith("Raffle__NotEnoughETHEntered")

  (and similar) with

  await expect(raffle.enterRaffle()).to.be.revertedWithCustomError(raffle, "Raffle__NotEnoughETHEntered")

• replaced interval.toNumber() with Number(interval)
• replace vrfCoordinatorV2Mock.address with vrfCoordinatorV2Mock.getAddress()
  • but not for the freshly deployed raffle
• using "@chainlink/contracts" version 0.8 instead of 0.4
  • the raffle contract must be added to the mock coordinator, otherwise requests will be rejected with reverted with custom error 'InvalidConsumer()':

    if (developmentChains.includes(network.name)) {
        // add the raffle as a consumer
        await vrfCoordinatorV2Mock.addConsumer(subscriptionId, raffle.address)
    }

  • for performUpkeep use "0x" as argument instead of [] (this could be an ethers v6 thing)
• for static calls replace raffle.callStatic.checkUpkeep([]) with raffle.checkUpkeep.staticCall("0x") (and similar)
• replace accounts[winnerIndex].getBalance() with ethers.provider.getBalance(accounts[winnerIndex].address)