'length' Error while Deploying on Mumbai Testnet only.

[Mark-Four]

I have a peculiar issue. I get the following error, only when I'm deploying to the Mumbai Testnet:

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

I have deployed successfully on the local hardhat network with mocks and on rinkeby. I'm only getting this error when trying to deploy to mumbai testnet.

This error is similar to #69, answered by @PatrickAlphaC . So I followed his solution (I had already included the named accounts in the hardhat-config, since Patrick mentions it somewhere in Lesson 8).

However, It's still throwing up the same error.

My namedAccounts object from 'hardhat-config.js' -

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

The code snippet that's throwing the error -

const { network, ethers } = require("hardhat")
const { developmentChains, networkConfig } = require("../helper-hardhat-config")
const { verify } = require("../utils/verify")
const VRF_SUB_FUND_AMOUNT = "1000000000000000000000"

module.exports = async function ({ getNamedAccounts, deployments }) {
    const { deploy, log } = deployments
    const { deployer } = await getNamedAccounts()
    const chainId = network.config.chainId
    let vrfCoordinatorV2Address, subscriptionId

    if (developmentChains.includes(network.name)) {
        const vrfCoordinatorV2Mock = await ethers.getContract("VRFCoordinatorV2Mock")
        vrfCoordinatorV2Address = vrfCoordinatorV2Mock.address
        const transactionResponse = await vrfCoordinatorV2Mock.createSubscription()
        const transactionReceipt = await transactionResponse.wait(1)
        subscriptionId = transactionReceipt.events[0].args.subId
        await vrfCoordinatorV2Mock.fundSubscription(subscriptionId, VRF_SUB_FUND_AMOUNT)
    } else {
        vrfCoordinatorV2Address = networkConfig[chainId]["vrfCoordinatorV2"]
        subscriptionId = networkConfig[chainId]["subscriptionId"]
    }

    const entranceFee = networkConfig[chainId]["entranceFee"]
    const gasLane = networkConfig[chainId]["gasLane"]
    const callbackGasLimit = networkConfig[chainId]["callbackGasLimit"]
    const interval = networkConfig[chainId]["interval"]
    const args = [
        vrfCoordinatorV2Address,
        entranceFee,
        gasLane,
        subscriptionId,
        callbackGasLimit,
        interval,
    ]
    const raffle = await deploy("Raffle", {
        from: deployer,
        args: args,
        log: true,
        waitConfirmations: network.config.blockConfirmations || 1,
    })

[krakxn]

When does it lead to TypeError: Cannot read properties of undefined (reading 'length'), when you do yarn hardhat deploy xyz --network xyzmumbai?

[Mark-Four]

This is the portion that leads to the error. Before this, all variables are created and values stored successfully.

const raffle = await deploy("Raffle", {
        from: deployer,
        args: args,
        log: true,
        waitConfirmations: network.config.blockConfirmations || 1

[krakxn]

Show the entire code for the file which contains this code snippet.

[Mark-Four]

Here it is:

const { network, ethers } = require("hardhat")
const { developmentChains, networkConfig } = require("../helper-hardhat-config")
const { verify } = require("../utils/verify")
const VRF_SUB_FUND_AMOUNT = "1000000000000000000000"

module.exports = async function ({ getNamedAccounts, deployments }) {
    const { deploy, log } = deployments
    const { deployer } = await getNamedAccounts()
    const chainId = network.config.chainId
    let vrfCoordinatorV2Address, subscriptionId

    if (developmentChains.includes(network.name)) {
        const vrfCoordinatorV2Mock = await ethers.getContract("VRFCoordinatorV2Mock")
        vrfCoordinatorV2Address = vrfCoordinatorV2Mock.address
        const transactionResponse = await vrfCoordinatorV2Mock.createSubscription()
        const transactionReceipt = await transactionResponse.wait(1)
        subscriptionId = transactionReceipt.events[0].args.subId
        await vrfCoordinatorV2Mock.fundSubscription(subscriptionId, VRF_SUB_FUND_AMOUNT)
    } else {
        vrfCoordinatorV2Address = networkConfig[chainId]["vrfCoordinatorV2"]
        subscriptionId = networkConfig[chainId]["subscriptionId"]
    }

    const entranceFee = networkConfig[chainId]["entranceFee"]
    const gasLane = networkConfig[chainId]["gasLane"]
    const callbackGasLimit = networkConfig[chainId]["callbackGasLimit"]
    const interval = networkConfig[chainId]["interval"]
    const args = [
        vrfCoordinatorV2Address,
        entranceFee,
        gasLane,
        subscriptionId,
        callbackGasLimit,
        interval,
    ]
    const raffle = await deploy("Raffle", {
        from: deployer,
        args: args,
        log: true,
        waitConfirmations: network.config.blockConfirmations || 1,
    })

    if (!developmentChains.includes(network.name) && process.env.ETHERSCAN_API_KEY) {
        log("Verifying...")
        await verify(raffle.address, args)
    }

    log("-------------------")
}

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

[krakxn]

@Mark-Four Found the problem, the following should fix your code:

 const arguments = [
        vrfCoordinatorV2Address,
        subscriptionId,
        networkConfig[chainId]["gasLane"],
        networkConfig[chainId]["keepersUpdateInterval"],
        networkConfig[chainId]["raffleEntranceFee"],
        networkConfig[chainId]["callbackGasLimit"],
    ]
    const raffle = await deploy("Raffle", {
        from: deployer,
        args: arguments,
        log: true,
        waitConfirmations: waitBlockConfirmations,
    })

The problem lies in the precedence of the arguments, it should match that of the contructor's

[Mark-Four]

Hi @krakxn ,
Thank you for replying.
I checked the order of precedence for the constructor, and I'm passing the arguments correctly as per my Raffle.sol contract constructor.
I am able to deploy to the local network and to rinkeby.
I'm only facing an issue deploying to the Mumbai Testnet.
Tried everything. Rewrote the entire hardhat-config from scratch and I'm still facing the same error.
I have a feeling it's got to do with the namedAccounts declaration i.e 'deployer' in hardhat-config.

[SrikanthAlva]

Have you added accounts to the Mumbai testnet in hardhat.config.ts?

[Mark-Four]

Yes, this is my hardhat-config.js

require("@nomiclabs/hardhat-waffle")
require("@nomiclabs/hardhat-etherscan")
require("hardhat-deploy")
require("solidity-coverage")
require("hardhat-gas-reporter")
require("hardhat-contract-sizer")
require("dotenv").config()

const RINKEBY_RPC_URL = process.env.RINKEBY_RPC_URL
const MUMBAI_RPC_URL = process.env.MUMBAI_RPC_URL
const PRIVATE_KEY = process.env.PRIVATE_KEY
const COINMARKETCAP_API_KEY = process.env.COINMARKETCAP_API_KEY
const ETHERSCAN_API_KEY = process.env.ETHERSCAN_API_KEY

module.exports = {
    defaultNetwork: "hardhat",
    networks: {
        hardhat: {
            chainId: 31337,
            blockConfirmations: 1,
        },
        rinkeby: {
            chainId: 4,
            blockConfirmations: 6,
            url: RINKEBY_RPC_URL,
            accounts: [PRIVATE_KEY],
        },
        mumbai: {
            chainId: 80001,
            blockConfirmations: 6,
            url: MUMBAI_RPC_URL,
            account: [PRIVATE_KEY],
        },
    },
    gasReporter: {
        enabled: false,
        currency: "USD",
        outputFile: "gas-report.txt",
        noColors: true,
        coinmarketcap: process.env.COINMARKETCAP_API_KEY,
    },
    solidity: "0.8.9",
    namedAccounts: {
        deployer: {
            default: 0,
        },
        users: {
            default: 0,
        },
    },
    mocha: {
        timeout: 300000,
    },
    etherscan: {
        apiKey: {
            rinkeby: "IEN62VTX774ZZG67AUG2X56YT2EX86FIZ3",
        },
    },
}

[PatrickAlphaC]

9 times out of 10 this is the error:

#829

[Mark-Four]

Hi @PatrickAlphaC ,

1. The marked answer suggests we add namedAccounts to hardhat-config.js. I've already done that, since you'd done it in Lesson 9. (Code snippet posted above)

2. The marked answer also suggests that we check the spelling of the MockV3Aggregator. The contract is deploying correctly on localhost and hardhat and even on rinkeby. The error only comes up when deploying on the mumbai testnet.

3. The reason I'm trying to deploy to the mumbai testnet is becasue when I tried with rinkeby, I was facing an error while creating a subscription on chainlink. All would go smoothly, till the Add funds section. I would add LINK, the tx would be confirmed, but the page would refresh to a 403 error. When I'd refresh, it was as if I'd never subscribed at all. I had to go through the entire process again, only to receive the same error.

4. I tried deploying to goerli, thinking that the alchemy rinkeby node may be misbehaving (I'd received an email from alchemy saying they're stopping support for rinkeby and we should switch to goerli). However, ChainLink doesn't have a goerli vrfCoordinator address. And so I had to try on another testnet, and Chainlink supports the Mumbai Testnet.

5. Debugger : I've placed a break point incrementally in the deploy script. The debugger catches the error when we're finally deploying here -

const raffle = await deploy("Raffle", {
        from: deployer,
        args: args,
        log: true,
        waitConfirmations: network.config.blockConfirmations || 1,
    })

[alymurtazamemon]

@Mark-Four Can you push it to GitHub and leave a link here?

[Mark-Four]

Hi @alymurtazamemon ,

1. Github repo link is - hardhat-lottery
2. Yes, I've added the mumbai network Id and relevant values to the helper-hardhat-config.

[alymurtazamemon]

@Mark-Four Ok, I will check and let you know.

[alymurtazamemon]

@Mark-Four I checked your code, now it is working, here was mistake.

accounts: [PRIVATE_KEY],

It is accounts not account

[Mark-Four]

Yo @alymurtazamemon !!!! Thank you so much man. It absolutely worked. You're a savior. I wasn't able to move on to Lesson 10 because I was still figuring it out!
You're a legend.

[PatrickAlphaC]

He is :)