TypeError: Cannot read properties of undefined (reading 'keccak256')

[wwwbaraccuda]

When i try to run script mockOffChain.js, i get this error :

Here's the code of mockOffChain.js (i copied it from github) :

const { ethers, network } = require("hardhat")

async function mockKeepers() {
    const raffle = await ethers.getContract("Raffle")
    const checkData = ethers.utils.keccak256(ethers.utils.toUtf8Bytes(""))
    const { upkeepNeeded } = await raffle.callStatic.checkUpkeep(checkData)
    if (upkeepNeeded) {
        const tx = await raffle.performUpkeep(checkData)
        const txReceipt = await tx.wait(1)
        const requestId = txReceipt.events[1].args.requestId
        console.log(`Performed upkeep with RequestId: ${requestId}`)
        if (network.config.chainId == 31337) {
            await mockVrf(requestId, raffle)
        }
    } else {
        console.log("No upkeep needed!")
    }
}

async function mockVrf(requestId, raffle) {
    console.log("We on a local network? Ok let's pretend...")
    const vrfCoordinatorV2Mock = await ethers.getContract("VRFCoordinatorV2Mock")
    await vrfCoordinatorV2Mock.fulfillRandomWords(requestId, raffle.address)
    console.log("Responded!")
    const recentWinner = await raffle.getRecentWinner()
    console.log(`The winner is: ${recentWinner}`)
}

mockKeepers()
    .then(() => process.exit(0))
    .catch((error) => {
        console.error(error)
        process.exit(1)
    })

Anyone know how to fix this error?

[Nlferu]

Hi @wwwbaraccuda

You are keep asking same questions over and over again and the issue is still the same. You are using different ethers version. If you dont want to match course ethers version you need to fix your syntax to new ethers v6, otherwise downgrade your ethers to v5.

We have already explained everything to you here: LINK

But you have ignored our response and keep getting same errors.

[wwwbaraccuda]

Sorry mate, i didn't mean to be rude or ignoring your explanation, but I'm kinda new on this whole thing.

I couldn't fully understand the discussion on that particular link coz it's too hard for me to understand it and I couldn't keep up. That's why, on the previous topic on that link, I kinda try to figured out by myself (since I must wait for the discussion to finished and the conclusion is made). And that's why, on the previous link I tell that "somehow I made it".

I said that not because I ignored the explanation, but it merely just announce my success on that particular topic (which I achieve through my trials and errors process) and to not make the thread hanging. I also leave my repo link coz I think maybe you guys want to see it. Ofc I read all the discussion and the explanation, but problem within dependencies is really tough for me to understand.

Back to this current topic, I didn't know that this errors also about syntax problem. I assume (from your explanation), since I already change ethers version to version 6, I must change syntax : const checkData = ethers.utils.keccak256(ethers.utils.toUtf8Bytes("")) into ether v6 syntax? If so, that's problem coz i don't know what must i changed it into.

Once again, sorry for this misunderstanding. I'll study as hard as I can.

[Nlferu]

@wwwbaraccuda

We are here to help, if you do not understand some of ours explanation keep asking, we will try to explain it better. Regarding your syntax question, if you are using ethers v6 you need to use different syntax yes. As you are new to coding figuring out correct syntax from ethers documentation might be challenging that is why I encourage you to just follow course Patrick created. He was using ethers v5 and whole course is using ethers v5 syntax, so you can easily check any repository you want and see how things were done there. If you will just keep using course repository dependencies for packages all should work without any issues. You can try to recreate all codes and lessons with ethers v6 after you finish this course, but there is no point to struggle so much now as you are beginner.

To follow course with ethers v5 just follow below steps:

1. Create fresh folder for your lesson project
2. In that folder just create all folders, which Patrick is using, so for example contracts, scripts etc. (just check lesson repository)
3. Create package.json file go to lesson repository and copy code from package.json into your package.json.
4. Now install all required packages (ones Patrick is using in course) by writing yarn in your terminal -> it should create node_modules folder for you with all required dependencies, which comes from that package.json you have copied.
5. Just keep following course lesson and do not install anything else along with Patrick as you already have all what you need in your project by copying package.json and installing its packages.

[Blockchain-Oracle]

When i try to run script mockOffChain.js, i get this error :

Here's the code of mockOffChain.js (i copied it from github) :

const { ethers, network } = require("hardhat")

async function mockKeepers() {
    const raffle = await ethers.getContract("Raffle")
    const checkData = ethers.utils.keccak256(ethers.utils.toUtf8Bytes(""))
    const { upkeepNeeded } = await raffle.callStatic.checkUpkeep(checkData)
    if (upkeepNeeded) {
        const tx = await raffle.performUpkeep(checkData)
        const txReceipt = await tx.wait(1)
        const requestId = txReceipt.events[1].args.requestId
        console.log(`Performed upkeep with RequestId: ${requestId}`)
        if (network.config.chainId == 31337) {
            await mockVrf(requestId, raffle)
        }
    } else {
        console.log("No upkeep needed!")
    }
}

async function mockVrf(requestId, raffle) {
    console.log("We on a local network? Ok let's pretend...")
    const vrfCoordinatorV2Mock = await ethers.getContract("VRFCoordinatorV2Mock")
    await vrfCoordinatorV2Mock.fulfillRandomWords(requestId, raffle.address)
    console.log("Responded!")
    const recentWinner = await raffle.getRecentWinner()
    console.log(`The winner is: ${recentWinner}`)
}

mockKeepers()
    .then(() => process.exit(0))
    .catch((error) => {
        console.error(error)
        process.exit(1)
    })

Anyone know how to fix this error?

@wwwbaraccuda you should know that the struggles you face as a beginner makes you a better developer.. keep coding! dont give up

heres the solution to your code using ethers version 6

const checkData = ethers.utils.keccak256(ethers.utils.toUtf8Bytes("")) 

TO

const checkData = ethers.keccak256(ethers.toUtf8Bytes("")) 

NOTE!! ethers.utils is no longer avaliable on version 6

other troubles you may face along the way is upkeepNeeded

 const { upkeepNeeded } = await raffle.callStatic.checkUpkeep(checkData)

the version 6 syntax for the above code is

  const { upkeepNeeded } = await raffle.checkUpkeep.staticCall(checkData);

other troubles you may face along the way is requestID

 const requestId = txReceipt.events[1].args.requestId

hard code requestId as 1
for version 6 of ethers, i`m still struggling to learn how to read events

This is where it becomes more Art than Science :)

Remeber to set upkeedNeed to True

here are the requirements for it to return True
Number of Players in raffle > 1
Balance of Raflle > 0
Time interval > 30 seconds
Add consumer Address

//Enter Raffle
await raffle.enterRaffle({ value: ethers.parseEther("0.2") });

//Increase Time 
  interval = await raffle.getInterval();
  await time.increase(Number(interval) + 1);

// Add consumer address
  subscriptionId = await raffle.getSubscriptionId();
  const vrfCoordinatorV2Mock = await ethers.getContract("VRFCoordinatorV2Mock");
  await vrfCoordinatorV2Mock.addConsumer(
    subscriptionId,
    await raffle.getAddress()
  );

  interval = await raffle.getInterval();
  await time.increase(Number(interval) + 1);

Those two syntax above are from version 6 you`d have to import time from

const { time } = require("@nomicfoundation/hardhat-toolbox/network-helpers");

please remeber to mark this as answer thank you 🥇 👍

@PatrickAlphaC @wwwbaraccuda

[wbshobhit1]

const requestId = txReceipt.events[1].args.requestId
USE THIS :-
const requestId = raffle.interface.parseLog(txReceipt.logs[1]).args.requestId;