Lesson 12 Part 4 | DecentralizedStablecoin.sol-src

[Rolko-u]

I'm trying to follow the course by typing the code in my vs code, but I get this error when I create my contract:
No arguments passed to the base constructor. Specify the arguments or mark "DecentralizedStableCoin" as abstract Here's my code:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

import {ERC20Burnable, ERC20} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";

contract DecentralizedStableCoin is ERC20Burnable, Ownable {
    constructor() ERC20("DecentralizedStableCoin", "DSC") {}
}

The error only appears when I set the Ownable as the parent contract. Need some help please

[pacelliv]

OpenZeppelin updated their smart contract library so apparently the new Ownable contract requires an initial owner as a constructor argument.

Inspect Ownable to see if that's the case. If it is, you can do:

• Ownable(msg.sender), or
• constructor(address owner) ERC20("DecentralizedStableCoin", "DSC") Ownable(owner) {}

[manu-acho]

I faced the same issue, how does this impact the DeployDSC.s.sol in the setup of the run() function.
I have the contructor for DecentralizedStableCoin setup as

constructor(address initialOwner) ERC20("DecentralizedStableCoin", "DSC") Ownable(initialOwner){}

and in the Deploy script

contract DeployDSC is Script {
    function run() external returns (DecentralizedStableCoin, DSCEngine) {
        vm.startBroadcast();
        DecentralizedStableCoin dsc = new DecentralizedStableCoin(address(this));
        vm.stopBroadcast();
    }
}

I'm a bit worried I'd face issues with testing if this isn't setup correctly so any clues on how you managed this with the OpenZeppelin update would be much appreciated.

[PrintRH]

That's a good question looking ahead.

You're right that you will run into testing problems because the initialOwner address does not match the DecentralizedStableCoin(address(this)) instance. What you can do is generate the public address of the deployerKey and pass it to the dsc variable (the section covering the part to pass deployerKey to vm.startBroadcast(deployerKey) will be covered by Patrick C. as you progressively watch through the videos).

Here's a code snippet of what that looks like:

        vm.startBroadcast(deployerKey);
        address deployerPublicAddress = vm.addr(deployerKey);
        DecentralizedStableCoin dsc = new DecentralizedStableCoin(deployerPublicAddress);
        // rest of code...
        vm.stopBroadcast();

In the example above, you are then correctly matching the address that initiated the transaction which is also the initialOwner of DecentralizedStableCoin contract. With this setup, you should be good with running tests.

[manu-acho]

Thanks a lot!!