I get error saying "invalid contract address or ENS name" when I try to run Interact.js script from Alchemy's Hello world smart contract tutorial

Question

I was following This tutorial from Alchemy to build a HelloWorld smart contract.

After successfully deploying it to alchemy, when I wrote the 'Interact.js' script from the tutorial and tried to run it, it got me the following error

my solidity compiler version: 0.8.0

PS E:\programming\Tutorials\Blockchain tutorials\hello world alchemy> npx hardhat run scripts/interact.js

E:\programming\Tutorials\Blockchain tutorials\hello world alchemy\node_modules\@ethersproject\logger\src.ts\index.ts:225
        const error: any = new Error(message);
                           ^
Error: invalid contract address or ENS name (argument="addressOrName", value=undefined, code=INVALID_ARGUMENT, version=contracts/5.5.0)
    at Logger.makeError (E:\programming\Tutorials\Blockchain tutorials\hello world alchemy\node_modules\@ethersproject\logger\src.ts\index.ts:225:28)
    at Logger.throwError (E:\programming\Tutorials\Blockchain tutorials\hello world alchemy\node_modules\@ethersproject\logger\src.ts\index.ts:237:20)
    at Logger.throwArgumentError (E:\programming\Tutorials\Blockchain tutorials\hello world alchemy\node_modules\@ethersproject\logger\src.ts\index.ts:241:21)
    at Contract.BaseContract (E:\programming\Tutorials\Blockchain tutorials\hello world alchemy\node_modules\@ethersproject\contracts\src.ts\index.ts:706:20)
    at new Contract (E:\programming\Tutorials\Blockchain tutorials\hello world alchemy\node_modules\@ethersproject\contracts\lib\index.js:1047:42)
    at Object.<anonymous> (E:\programming\Tutorials\Blockchain tutorials\hello world alchemy\scripts\interact.js:17:28)
    at Module._compile (node:internal/modules/cjs/loader:1108:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1137:10)
    at Module.load (node:internal/modules/cjs/loader:988:32)
    at Function.Module._load (node:internal/modules/cjs/loader:828:14)

This is my Smart contract code:

//SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

contract HelloWorld {
    event UpdatedMessages( string oldStr, string newStr);

    string public message;

    constructor( string memory initMessage ) {
        message = initMessage;
    }


    function update(string memory newMessage) public {
        string memory oldMessage = message;
        message = newMessage;

        emit UpdatedMessages(oldMessage, message);

    }
}

This is my interact.js code:

const API_KEY = process.env.API_KEY;
const PRIVATE_KEY = process.env.PRIVATE_KEY;
const CONTRACT_ADDRESS = process.env.CONTRACT_ADDRESS;
const { ethers } = require("hardhat");
const contract = require("../artifacts/contracts/HelloWorld.sol/HelloWorld.json");

//provider - alchemy
const alchemyProvider = new ethers.providers.AlchemyProvider(
  (network = "goerli"),
  API_KEY
);

//signer - Me
const signer = new ethers.Wallet(PRIVATE_KEY, alchemyProvider);

// contract instance
const helloWorldContract = new ethers.Contract(
  CONTRACT_ADDRESS,
  contract.abi,
  signer
);

const main = async () => {
  const message = await helloWorldContract.message();
  console.log("The message is: " + message);
  console.log("updating the message...");

  const tx = await helloWorldContract.update(
    "This is the new updated message."
  );

  await tx.wait();

  const newMessage = await helloWorldContract.message();
  console.log("The new message is: " + newMessage);
};

main()
  .then(() => process.exit(0))
  .catch((err) => {
    console.error(err);
    process.exit(1);
  });

My hardhat.config.js code:

/**
 * @type import('hardhat/config').HardhatUserConfig
 */

require('dotenv').config();
require("@nomiclabs/hardhat-ethers");

const { API_URL, PRIVATE_KEY } = process.env;

module.exports = {
  solidity: "0.8.0",
  defaultNetwork: "goerli",
  networks: {
    hardhat: {},
    goerli: {
      url: API_URL,
      accounts: [`0x${PRIVATE_KEY}`]
    }
  }
  // api key of alchemy
  // wallet password
};

Answer 1

Like Richard mentioned in the comments, it seems that CONTRACT_ADDRESS is not set correctly, based on the error you're seeing:

Error: invalid contract address or ENS name

Currently you're pulling CONTRACT_ADDRESS from your .env file. You should be able to fix this problem by updating your environment variable to the correct address.

For example, if this is your .env:

API_URL=https://eth-goerli.alchemyapi.io/v2/<redacted>
PRIVATE_KEY=<redacted>
CONTRACT_ADDRESS=0x5180db8f5c931aae63c74266b211f580155ecac8 // double check this address

You should check if the contract address 0x5180db8f5c931aae63c74266b211f580155ecac8 is actually a deployed contract on the Goerli network.

You can use etherscan to check for example: https://goerli.etherscan.io/

If it's not there, then you just need to update with the correct CONTRACT_ADDRESS!

Hope that helps :)