BTRFLYV2 Manual Review Findings

BTR-01M: Deviation From BTRFLY V1

Type	Severity	Location
Standard Conformity		BTRFLYV2.sol:L15-L30

Description:

The new BTRFLY V2 token implementation lacks important functions that were present in the previous implementation, such as the burn and burnFrom functions that make the current V1 -> V2 migration possible.

Example:

Copy
15contract BTRFLYV2 is AccessControl, ERC20("BTRFLY", "BTRFLY", 18) {
16    bytes32 public constant MINTER_ROLE = "MINTER_ROLE";
17
18    constructor() {
19        _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);
20    }
21
22    /**
23        @notice Mint tokens
24        @param  to      address  Address to receive tokens
25        @param  amount  uint256  Amount to mint
26     */
27    function mint(address to, uint256 amount) external onlyRole(MINTER_ROLE) {
28        _mint(to, amount);
29    }
30}

Recommendation:

We advise the missing features to be carefully evaluated and potentially re-introduced depending on the business use case of BTRFLYV2. Additionally, we would like to note that the new BTRFLYV2 token contains 18 decimals whilst the original token contained 9 decimals, a discrepancy which may case any previous implementations being upgraded to misbehave.

Alleviation:

The burn function that was present in the original implementation has been re-introduced permitting future upgrades to be seamless similarly to the V1 -> V2 conversion and thus alleviating this exhibit.