Fractional v2 contest - Tomio's results

Title: Use safeTransfer/safeTransferFrom consistently instead of transfer/transferFrom

Impact: It is good to add a require() statement that checks the return value of token transfers or to use something like OpenZeppelin’s safeTransfer/safeTransferFrom unless one is sure the given token reverts in case of a failure. Failure to do so will cause silent failures of transfers and affect token accounting in contract.

Proof of Concept: BaseVault.sol#L65

Recommended Mitigation Steps Consider using safeTransfer/safeTransferFrom or require() consistently.

Reference: here

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Title: Consider make constant as private to save gas

Proof of Concept: FERC1155.sol#L15-L17 Buyout.sol#L35-L37

Recommended Mitigation Steps: I suggest changing the visibility from public to internal or private

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Title: Using unchecked and prefix increment is more effective for gas saving:

Proof of Concept: Vault.sol#L78 Vault.sol#L104

Recommended Mitigation Steps: Change to:

  for (uint256 i = 0; i < length;) {
        // ...
  unchecked { ++i; }
    }

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Title: Set as immutable can save gas

Proof of Concept: BaseVault.sol#L19

Recommended Mitigation Steps: can be set as immutable, which already set once in the constructor

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Title: abi.encode() is less efficient than abi.encodePacked()

Proof of Concept: Minter.sol#L26

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Title: empty constructor

Proof of Concept: MerkleBase.sol#L8

Recommended Mitigation Steps: Remove if unused for gas saving

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