totalNftMintCount can be replaced with ERC721 totalSupply()

[code423n4]

Handle

pauliax

Vulnerability details

Impact

I can't find a reason why totalNftMintCount in Factory can't be replaced with ERC721 totalSupply() to make it less error-prone. As nfthub.mint issues a new token it should automatically increment totalSupply and this assignment won't be needed:
totalNftMintCount = totalNftMintCount + _tokenURIs.length;
Also in function setNftHubAddress you need to manually set _newNftMintCount if you want to change nfthub so an invalid value may crash the system. totalSupply() will eliminate totalNftMintCount and make the system more robust.

Recommended Mitigation Steps

Replace totalNftMintCount with nfthub totalSupply() in Factory contract.

[mcplums]

This is a good one, would indeed make it less error prone

[Splidge]

Sometimes what looks like a small fix just takes you all the way down the rabbithole, this was one of them. totalSupply() isn't included by default so I had to import the Enumerable extension.
fixed here