Testing on real blockchain data without tokens - https://www.youtube.com/watch?v=VGZb2orvYJE

Checker.sol

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.7.0 <0.9.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

contract Checker {

    function check(address _token, address user) view public returns (uint256) {
        return IERC20(_token).balanceOf(user);
    }
}

Commands.txt

// to create hardhat project

npx hardhat init

// to run a local blockchain

npx hardhat node

// to fork a blockchain and run locally

npx hardhat node --fork "RPC_URL"

// to connect to locally running blockchain node

npx hardhat console --network localhost

hardhat.config.js

require("@nomicfoundation/hardhat-toolbox");

/** @type import('hardhat/config').HardhatUserConfig */
module.exports = {
  solidity: "0.8.17",
  networks: {
    hardhat: {
      forking: {
        url: "https://cloudflare-eth.com/",
      }
    }
  }

};

Awesome, thanks for this. You are really great teacher and programmer. 😘