AVOID FLOATING PRAGMAS: THE VERSION SHOULD BE LOCKED
The pragma declared across the contract range from ^0.8.4- ^0.8.15. Locking the pragma (for e.g. by not using ^ in pragma solidity 0.8.15) ensures that contracts do not accidentally get deployed using an older compiler version with unfixed bugs. (see here)
EVENT IS MISSING INDEXED FIELDS
Each event should use three indexed fields if there are three or more fields.
AVOID FLOATING PRAGMAS: THE VERSION SHOULD BE LOCKED
The pragma declared across the contract range from ^0.8.4- ^0.8.15. Locking the pragma (for e.g. by not using ^ in pragma solidity 0.8.15) ensures that contracts do not accidentally get deployed using an older compiler version with unfixed bugs. (see here)
use
string.concat()
instead ofabi.encodePacked()
Refer to Solidity Documents.