GovernanceToken.sol

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

/**
 * @dev Only the holder of this ERC20 token can participate in voting process.
 */

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/draft-ERC20Permit.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Votes.sol";

contract GovernanceToken is ERC20, ERC20Permit, ERC20Votes {
    uint256 public s_maxSupply = 1000000 ether; // 1000000 * 10 ** 18

    constructor()
        ERC20("GovernanceToken", "GT")
        ERC20Permit("GovernanceToken")
    {
        _mint(msg.sender, s_maxSupply);
    }

    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal override(ERC20, ERC20Votes) {
        super._afterTokenTransfer(from, to, amount);
    }

    function _mint(
        address to,
        uint256 amount
    ) internal override(ERC20, ERC20Votes) {
        super._mint(to, amount);
    }

    function _burn(
        address account,
        uint256 amount
    ) internal override(ERC20, ERC20Votes) {
        super._burn(account, amount);
    }
}