UUPS and SPDX in smart contract Remix

Smart Contracts
1

Hi,

there is an error appearing when we are deploying smart contract. If anyone there can share solution, we would appreciate. The smart contract shall be deployed from remix to moonbeam, and etherscan. Code and error are shared below.

Error

/draftERC20PermitUpgradeable.sol:16:1:
|
16 | contract TestSc is
Initializable, E ...
hMintUpgradeable, UUPSUpgradeable
{
| ^ (Relevant source part
starts here and spans across
multiple lines).
Note: The previous declaration is
here:
-->
.deps/npm/@openzeppelin/contractsupgradeable/token/ERC20/extensions
/draftERC20PermitUpgradeable.sol:9:1:
|
9 | import
"@openzeppelin/contractsupgradeable/token/ERC20/extensions
/draftERC20PermitUpgradeable.sol";
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

And below is the code

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.2;

import "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";

import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC20BurnableUpgradeable.sol";

import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC20SnapshotUpgradeable.sol";

import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";

import "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";

import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/draft-ERC20PermitUpgradeable.sol";

import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC20VotesUpgradeable.sol";

import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC20FlashMintUpgradeable.sol";

import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";

import "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";

/// @custom:security-contact test@test.com

contract TestSc is Initializable, ERC20Upgradeable, ERC20BurnableUpgradeable, ERC20SnapshotUpgradeable, OwnableUpgradeable, PausableUpgradeable, ERC20PermitUpgradeable, ERC20VotesUpgradeable, ERC20FlashMintUpgradeable, UUPSUpgradeable {

/// @custom:oz-upgrades-unsafe-allow constructor

constructor() initializer {}

function initialize() initializer public {

    __ERC20_init("TestSc", "Sc");

    __ERC20Burnable_init();

    __ERC20Snapshot_init();

    __Ownable_init();

    __Pausable_init();

    __ERC20Permit_init("TestSc");

    __ERC20FlashMint_init();

    __UUPSUpgradeable_init();

    _mint(msg.sender, 100000000 * 10 ** decimals());

}

function snapshot() public onlyOwner {

    _snapshot();

}

function pause() public onlyOwner {

    _pause();

}

function unpause() public onlyOwner {

    _unpause();

}

function mint(address to, uint256 amount) public onlyOwner {

    _mint(to, amount);

}

function _beforeTokenTransfer(address from, address to, uint256 amount)

    internal

    whenNotPaused

    override(ERC20Upgradeable, ERC20SnapshotUpgradeable)

{

    super._beforeTokenTransfer(from, to, amount);

}

function _authorizeUpgrade(address newImplementation)

    internal

    onlyOwner

    override

{}

// The following functions are overrides required by Solidity.

function _afterTokenTransfer(address from, address to, uint256 amount)

    internal

    override(ERC20Upgradeable, ERC20VotesUpgradeable)

{

    super._afterTokenTransfer(from, to, amount);

}

function _mint(address to, uint256 amount)

    internal

    override(ERC20Upgradeable, ERC20VotesUpgradeable)

{

    super._mint(to, amount);

}

function _burn(address account, uint256 amount)

    internal

    override(ERC20Upgradeable, ERC20VotesUpgradeable)

{

    super._burn(account, amount);

}

}

We are trying to deploy the contract for token, which we can call and change.

We would like to add as well SPDX licence. If anyone has this experience as well, it is much appreciated.

Thank you.