Aave Lens contest - 0x1f8b's results

Low

1. There is a common practice of not checking the inputs during the construction of the contracts (constructor)

• LensHub.sol#L58-L59
• FollowNFT.sol#L49
• CollectNFT.sol#L30

2. There is a common practice of not checking the inputs during the initialization of the contracts (initialize)

• LensHub.sol#L70
• FollowNFT.sol#L60
• CollectNFT.sol#L42-L43

3. Logic around handle verification is not completely secure, it's allow handles like .......

• PublishingLogic.sol#L398-L410

GAS

1. The following structs could be optimized moving the position of certains values in order to save slot storages:

• move sig close to followModule in DataTypes.sol#L125
• move sig close to referenceModule in DataTypes.sol#L208, DataTypes.sol#L257 and DataTypes.sol#L294
• move sig close to follower in DataTypes.sol#L310
• move sig close to collector in DataTypes.sol#L328

2. Avoid declare variables before use it:

• revision could be moved to line 37

3. Emit the event before change the state in order to save one variable:

before:

    function setEmergencyAdmin(address newEmergencyAdmin) external override onlyGov {
        address prevEmergencyAdmin = _emergencyAdmin;
        _emergencyAdmin = newEmergencyAdmin;
        emit Events.EmergencyAdminSet(
            msg.sender,
            prevEmergencyAdmin,
            newEmergencyAdmin,
            block.timestamp
        );
    }

after:

    function setEmergencyAdmin(address newEmergencyAdmin) external override onlyGov {
        emit Events.EmergencyAdminSet(
            msg.sender,
            _emergencyAdmin,
            newEmergencyAdmin,
            block.timestamp
        );
        _emergencyAdmin = newEmergencyAdmin;
    }

This logic could be used to save gas in:

• LensHub.sol#L83-L92
• LensHub.sol#L850-L854
• ModuleGlobals.sol#L101-L106
• ModuleGlobals.sol#L108-L113
• LensMultiState.sol#L35-L39

4. Use delete instead of set to default value (false or 0)

• When whitelist=false in LensHub.sol#L107
• When whitelist=false in LensHub.sol#L113
• When whitelist=false in LensHub.sol#L123
• When toWhitelist=false in ModuleGlobals.sol#L118
• LensHub.sol#L926
• ApprovalFollowModule.sol#L85

5. Use storage keyword for save gas in order to cache a storage pointer.

• cache _dataByPublicationByProfile[profileId][pubId] in FeeCollectModule.sol#L75-L78
• cache _dataByPublicationByProfile[profileId][pubId] in LimitedFeeCollectModule.sol#L82-L86
• cache _dataByPublicationByProfile[profileId][pubId] in LimitedTimedFeeCollectModule.sol#L89-L94
• cache _dataByPublicationByProfile[profileId][pubId] in TimedFeeCollectModule.sol#L84-L88