ERC1155Enumerable Implement

When minting and burning tokens,the ERC1155Enumerable implementation does not correctly update the following states:

• uint256[] private _allTokens;
• mapping(uint256 => uint256) private _allTokensIndex;
• mapping(address => uint256) internal _currentIndex;

In particular:

• the _allTokens array length (and therefore the totalSupply()) always increases (never decreases)
• the _allTokensIndex[id] always increases
• the _curentIndex[from] always increases

contract HelperERC1155 is ERC1155Enumerable, ERC1155Holder {
    constructor() ERC1155("Test") {
    }
    function mint(uint256 id, uint256 amount) external {
        _mint(msg.sender, id, amount, bytes(""));
    }
    function burn(uint256 id, uint256 amount) external {
        _burn(msg.sender, id, amount);
    }
    function currentIndex(address owner) external view returns (uint256) {
        return _currentIndex[owner];
    }
    function allTokensIndex(uint256 id) external view returns (uint256) {
        return _allTokensIndex[id];
    }
    function allTokens(uint256 idx) external view returns (uint256) {
        return _allTokens[idx];
    }
    function idTotalSupply(uint256 id) external view returns (uint256) {
        return _idTotalSupply[id];
    }
}