QA Report

[code423n4]

#1 Missing natspec comment supply

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/mixins/collections/SequentialMintCollection.sol#L113

A function has a natspec comment to explain utility about function or parameter but natspec comment supply is missing.
So i suggest to add natspec comment for parameter supply.

#2 Missing natspec comment treasury

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/mixins/shared/FoundationTreasuryNode.sol#L47

A function has a natspec comment to explain utility about function or parameter but natspec comment treasury is missing.
So i suggest to add natspec comment for parameter treasury.

#3 Missing natspec comment all param in distributeFunds()

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/mixins/shared/MarketFees.sol#L98

A function has a natspec comment to explain utility about function or parameter but all natspec comment params is missing.
So i suggest to add natspec comment for all parameter.

#4 Missing natspec comment all param in getFees()

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/mixins/shared/MarketFees.sol#L385

A function has a natspec comment to explain utility about function or parameter but all natspec comment params is missing.
So i suggest to add natspec comment for all parameter.

#5 Missing indexed field

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/mixins/shared/MarketFees.sol#L71

Each event should use three indexed fields if there are three or more fields. add indexed in buyReferrer..

#6 Similiar name function()

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/libraries/ArrayLibrary.sol#L13-L28

there have two same function with similiar param, so we suggest to choose one of the function anda remove unused one.

#7 Remove unused code

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/mixins/nftDropMarket/NFTDropMarketFixedPriceSale.sol#L303

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/NFTDropCollection.sol#L253

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/mixins/collections/SequentialMintCollection.sol#L108

remove all unused code in contract before deploy the contract to increase readibility and saving gas fee.

#8 Unnecessary unchecked for 0.8.0 above

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/NFTDropCollection.sol#L174

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/NFTDropCollection.sol#L183

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/NFTDropCollection.sol#L276

https://github.com/code-423n4/2022-08-foundation/blob/792e00df429b0df9ee5d909a0a5a6e72bd07cf79/contracts/NFTCollection.sol#L265

According to Solidity documentation:
Prior to Solidity 0.8.0, arithmetic operations would always wrap in case of under- or overflow leading to widespread use of libraries that introduce additional checks. Since Solidity 0.8.0, all arithmetic operations revert on over- and underflow by default, thus making the use of these libraries unnecessary.

[HardlyDifficult]

Missing natspecs

Fair feedback -- for natspec we aim for complete coverage of the public interfaces but for internal/private/libraries we have some gaps in order to reduce redundancy, for those we aim to include comments where things are unclear or not obvious from the function and variable names.

BuyReferralPaid event should index buyReferrer

Agree but won't fix at this time. We have already started emitting this event on mainnet, to simplify integrations such as subgraph we are going to continue with this event as is. However it's a good catch and I agree that buyReferrer ideally would have been indexed here.

Similiar name function()

Fair feedback but going to leave as is. These are library functions which do the same thing, just operating on different types.

Remove unused code

Invalid - these instances have those params due to inheritance requirements.

Unnecessary unchecked for 0.8.0 above

Invalid. Unchecked is a gas optimization that can be used when math is known to be safe.