Mock a mainnet contract dynamically

mockContract.ts

import fetch from 'node-fetch';
import { smock } from '@defi-wonderland/smock';

async function deployMockContractFromAddress(contractAddress: string, etherscanKey: string) {
    const abi = await fetch(`https://api.etherscan.io/api?module=contract&action=getabi&address=${contractAddress}&apikey=${etherscanKey}`)
        .then(response => response.json())
        .then(data => JSON.parse(data['result']));

    return smock.fake(abi, {address: contractAddress});
}

smock docs