Trivia #27

trivia-27.sol

// SPDX-License-Identifier: MIT
pragma solidity 0.8.13;

contract A {
    error InvalidOwnerOrNewAddress(address newOwner);

    address public owner;

    constructor() {
        owner = msg.sender;
    }

    function changeOwner(address _newOwner) public {
        // Only an owner can set a new owner
        bool isOwner = (owner == msg.sender);
        bool isNewOwnerValid = (_newOwner != address(0));

        if (isOwner && isNewOwnerValid) {
            owner = _newOwner;
        }
        else {
            revert InvalidOwnerOrNewAddress(_newOwner);
        }
    }
}