Hardhat – Fix Warning: Calling an Account Which is Not a Contract

So you are trying to run a Hardhat blockchain with npx hardhat node, connect to it and deploy two contract to it.

This depends on your Hardhat network configurations, but my guess is that the deployment is not using your running node at all. Check whether it lists deployments when those are happening. My guess is that you are using a Hardhat blockchain which is started just for the deployment, and killed right after that. And since it's started anew, it starts with the same settings and gives you the same first contract address (both contracts are new, from the blockchain's point of view, since it was restarted).

I guess you should be able to target the running node simply with the --network localhost setting, as is explained here: https://hardhat.org/guides/deploying

This might be an issue with the line:

 uint public contractBalance = _token.balanceOf(contractAddress);

As you can see in your code, you want to assign the contract balance to contractBalance before the contractAddress has been updated. You might want to move all the initializations in the constructor. So, for this case, you would need to:

 constructor() {
        contractAddress = address(this);
        contractBalance = _token.balanceOf(contractAddress);
    }

Also, your _token is just a ERC20 instance. It needs a token address to actually get that balance you are looking for. I will recommend learning about interfaces. Your final constructor would be:

constructor(address _tokenAddress) {
            contractAddress = address(this);
            _token = ERC20Basic(_tokenAddress);
            contractBalance = _token.balanceOf(contractAddress);
        }