Lesson 7: "1) TypeError: Cannot read properties of undefined (reading 'length')

[ashrth]

The issue is copied below, I am facing it when I am trying to run FundMe.test.js

       "before each" hook for "sets the aggregator addresses correctly":
     ERROR processing /home/ash/hardhat-fund-me/deploy/00-deploy-mocks.js:
TypeError: Cannot read properties of undefined (reading 'length')

My mock.js file is:

const { network } = require("hardhat")
const {
    developmentChains,
    DECIMAL,
    INITIAL_ANSWER,
} = require("../helper-hardhat-config")
module.exports = async ({ getNamedAccounts, deployments }) => {
    const { deploy, log } = deployments
    const { deployer } = await getNamedAccounts()
    const chainId = network.config.chainId
    if (developmentChains.includes(network.name)) {
        log("Local network detected! Deploying mocks...")
        await deploy("MockV3Aggregator", {
            contract: "MockV3Aggregator",
            from: deployer,
            log: true,
            args: [DECIMAL, INITIAL_ANSWER],
        })
        log("Mocks Deployed")
        log("_________________________________________________________")
    }
}

module.exports.tags = ["all", "mocks"]

The FundMe.test.js file is:

const { deployments, ethers, getNamedAccounts, network } = require("hardhat")
const { assert } = require("chai")

describe("FundMe", async function () {
    let fundMe
    let deployer
    let mockV3Aggregator
    beforeEach(async function () {
        //deploying out FundMe ocntrac using hardhat-deploy
        deployer = (await getNamedAccounts()).deployer
        await deployments.fixture(["all"])
        fundMe = await ethers.getContract("FundMe", deployer)
        mockV3Aggregator = await ethers.getContract(
            "MockV3Aggregator",
            deployer
        )
    })

    describe("constructor", async function () {
        it("sets the aggregator addresses correctly", async function () {
            const response = await fundMe.priceFeed()
            assert.equal(response, mockV3Aggregator.address)
        })
    })
})

It seems the error is in line 11 which is await deployments.fixture(["all"]) as one of the error lines said at Context.<anonymous> (/home/ash/hardhat-fund-me/test/unit/FundMe.test.js:11:9)
I have tried going through every file given in the error details, could not make it work. Also, tried to add @nomiclabs/ethers package again.

Also, this is my third error in a day, so could anyone please tell me what exactly am I doing wrong? Because I faced my same error deploying deploy.fundMe.js on hardhat, then I installed all the dependencies and the code worked.
Is it happening because there are missing files because I am using the newer version of hardhat? because my helper.ts file from node_module also has 6 errors, most of them saying Argument of type 'string' is not assignable to parameter of type 'never'.

[alymurtazamemon]

@ashrth Make sure you have this in your hardhat.config.js file:

namedAccounts: {
  deployer: {
    default: 0,
  },
  player: {
    default: 1,
  },
},

[alymurtazamemon]

@ashrth if you still face an issue, then leave your repo link, I willl check the complete code.

[ashrth]

I have it in my hardhar.config @alymurtazamemon
Could you please check the the repo?
https://github.com/ashrth/hardhat-fund-me

[SidharthK2]

Could you share your helper config please?

[ashrth]

Thank you, @SidharthK2 but the issue got resolved.

[othaime-en]

Hey @ashrth i've checked your repo and there seems to be an error in your hardhat.config.js file. You had misplaced a closing } Check the PR i made. Hope this helps

[ashrth]

@othaime-en It worked, I cannot believe I was fiddling over such a thing, I feel embarrassed. Could you please explain how did you get to hardhat.config for this error and what exactly did you do? I want to save myself for future. I wish the error message was clear and simple enough because I had been looking at all the files from node_modules.

[othaime-en]

Hey @ashrth Your hardhat.config.js was like this initially.

module.exports = {
    solidity: {
        compilers: [{ version: "0.8.8" }, { version: "0.6.6" }],
 

        defaultNetwork: "hardhat",

        namedAccounts: {
            deployer: {
                default: 0,
            },
            users: {
                default: 1,
            },
        },
    },     // Take note of this.
}

From the code above, you failed to correctly enclose the solidity section as it was being enclosed by the second last } So effectively all the code between was being included as part of the solidity version. Meaning that the namedAccounts that held the deployer account section wasn't being read properly. With that code, you solidity section was like this

    solidity: {
        compilers: [{ version: "0.8.8" }, { version: "0.6.6" }],

        defaultNetwork: "hardhat",

        namedAccounts: {
            deployer: {
                default: 0,
            },
            users: {
                default: 1,
            },
        }, // It was being enclosed here So I moved the enclosing } up to its right position

So in the end the file should have been like this

module.exports = {
    solidity: {
        compilers: [{ version: "0.8.8" }, { version: "0.6.6" }],
    }, // I moved this up to here 

        defaultNetwork: "hardhat",

        namedAccounts: {
            deployer: {
                default: 0,
            },
            users: {
                default: 1,
            },
        },
}

[ashrth]

@othaime-en Awesome, you gained yourself a new follower on Github, thanks

[othaime-en]

Oh and... don't feel embarassed. I guarantee we've all made silly mistakes sometime in our development journeys. It's okay to make mistakes. It's how we learn.

[ashrth]

@othaime-en I guess you are right.