Lesson 14: Failed to get Chain Id, invalid URL

[jacobhay2626]

I have been trying to complete the nft lesson and have been running into this error when trying to deploy to a local network, this doesnt make much sense to me as I didnt think a URL was needed for deploying locally?

Nothing to compile
failed to get chainId, falling back on net_version...
An unexpected error occurred:

TypeError: Invalid URL

This is my basic nft contract:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.8;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";

contract BasicNft is ERC721 {
    string public constant TOKEN_URI =
        "ipfs://bafybeig37ioir76s7mg5oobetncojcm3c3hxasyd4rvid4jqhy4gkaheg4/?filename=0-PUG.json";
    uint256 private s_tokenCounter;

    constructor() ERC721("Dogie", "DOG") {
        s_tokenCounter = 0;
    }

    function mintNft() public returns (uint256) {
        _safeMint(msg.sender, s_tokenCounter);
        s_tokenCounter = s_tokenCounter + 1;
        return s_tokenCounter;
    }

    function tokenURI(uint256 tokenId) public view override returns (string memory) {
        return TOKEN_URI;
    }

    function getTokenCounter() public view returns (uint256) {
        return s_tokenCounter;
    }
}

this is the deploy script:

const { network } = require("hardhat")
const { developmentChains } = require("../helper-hardhat-config")
const { verify } = require("../utils/verify")

module.exports = async ({ getNamedAccounts, deployments }) => {
    const { deploy, log } = deployments
    const { deployer } = await getNamedAccounts()

    log("----------------------------------------------------")
    arguments = []
    const basicNft = await deploy("BasicNft", {
        from: deployer,
        args: arguments,
        log: true,
        waitConfirmations: network.config.blockConfirmations || 1,
    })

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

module.exports.tags = ["all", "basicnft", "main"]

helper-hardhat-config:

const networkConfig = {
    31337: {
        name: "localhost",
        ethUsdPriceFeed: "0x9326BFA02ADD2366b30bacB125260Af641031331",
        gasLane: "0xd89b2bf150e3b9e13446986e571fb9cab24b13cea0a43ea20a6049a85cc807cc", // 30 gwei
        mintFee: "10000000000000000", // 0.01 ETH
        callbackGasLimit: "500000", // 500,000 gas
    },
    // Price Feed Address, values can be obtained at https://docs.chain.link/docs/reference-contracts
    // Default one is ETH/USD contract on Kovan
    4: {
        name: "rinkeby",
        ethUsdPriceFeed: "0x8A753747A1Fa494EC906cE90E9f37563A8AF630e",
        vrfCoordinatorV2: "0x6168499c0cFfCaCD319c818142124B7A15E857ab",
        gasLane: "0xd89b2bf150e3b9e13446986e571fb9cab24b13cea0a43ea20a6049a85cc807cc",
        callbackGasLimit: "500000", // 500,000 gas
        mintFee: "10000000000000000", // 0.01 ETH
        subscriptionId: "1002", // add your ID here!
    },
}

const DECIMALS = "18"
const INITIAL_PRICE = "200000000000000000000"
const developmentChains = ["hardhat", "localhost"]

module.exports = {
    networkConfig,
    developmentChains,
    DECIMALS,
    INITIAL_PRICE,
}

and config.js file:

require("@nomiclabs/hardhat-waffle");
require("hardhat-gas-reporter");
require("@nomiclabs/hardhat-etherscan");
require("dotenv").config();
require("solidity-coverage");
require("hardhat-deploy");
// You need to export an object to set up your config
// Go to https://hardhat.org/config/ to learn more
/**
 * @type import('hardhat/config').HardhatUserConfig
 */

const MAINNET_RPC_URL =
  process.env.MAINNET_RPC_URL || process.env.ALCHEMY_MAINNET_RPC_URL || "";
const COINMARKETCAP_API_KEY = process.env.COINMARKETCAP_API_KEY || "";
const KOVAN_RPC_URL =
  process.env.KOVAN_RPC_URL ||
  "https://eth-mainnet.alchemyapi.io/v2/your-api-key";
const PRIVATE_KEY =
  process.env.PRIVATE_KEY ||
  "0x11ee3108a03081fe260ecdc106554d09d9d1209bcafd46942b10e02943effc4a";
const ETHERSCAN_API_KEY = process.env.ETHERSCAN_API_KEY || "";

module.exports = {
  defaultNetwork: "hardhat",
  networks: {
    hardhat: {
      chainId: 31337,
      forking: {
        url: MAINNET_RPC_URL,
      },
    },
    localhost: {
      chainId: 31337,
    },
    kovan: {
      url: KOVAN_RPC_URL,
      accounts: [PRIVATE_KEY],
      chainId: 42,
      blockConfirmations: 6,
    },
  },
  solidity: {
    compilers: [
      {
        version: "0.8.8",
      },
      {
        version: "0.6.12",
      },
      {
        version: "0.4.19",
      },
    ],
  },
  etherscan: {
    apiKey: ETHERSCAN_API_KEY,
  },
  gasReporter: {
    enabled: true,
    currency: "USD",
    outputFile: "gas-report.txt",
    noColors: true,
    // coinmarketcap: COINMARKETCAP_API_KEY,
  },
  namedAccounts: {
    deployer: {
      default: 0, // here this will by default take the first account as deployer
      1: 0, // similarly on mainnet it will take the first account as deployer. Note though that depending on how hardhat network are configured, the account 0 on one network can be different than on another
    },
  },
};

Any help appreciated.

EDIT:

I just tried running the deployment on the localhost network and got this error:

Error HH108: Cannot connect to the network localhost.
Please make sure your node is running, and check your internet connection and networks config

[krakxn]

You should comment out the following as so, and check it solves the problem:

/* forking: {
        url: MAINNET_RPC_URL,
      }, */

[jacobhay2626]

you my friend are a legend, thankyou

[jacobhay2626]

why did that work if you dont mind me asking?

[krakxn]

It forks the MAINNET_RPC_URL, which (forking) you are probably are aware of.

Put simply -- in a beginner-friendly way -- it takes a snapshot of the blockchain which you provide, and runs on that copy. So, if you fork the Ethereum blockchain you will have all the txns up until that point, and you can test as so.