Notional x Index Coop - Tadashi's results

Usage of pragma experimental ABIEncoderV2

Details: Consider removing L3 of wfCashLogic.sol, as:

1. ABIEncoderV2 is not considered experimental anymore since Solidity 0.7.4; and
2. ABIEncoderV2 is turned on by default since Solidity 0.8.0.

Usage of deprecated function safeApprove

Details: In L66-75 of wfCashBase.sol the function safeApprove from OpenZeppelin contracts are used, however these functions have been deprecated according to OpenZeppelin 4.x docs.

Split require to avoid using && opcode

Details: In L129-137 of wfCashLogic.sol consider changing the code

require(
            ac.hasDebt == 0x00 &&
            assets.length == 1 &&
            EncodeDecode.encodeERC1155Id(
                assets[0].currencyId,
                assets[0].maturity,
                assets[0].assetType
            ) == fCashID
        );

to the following version without the && operator:

require(ac.hasDebt == 0x00);
require(assets.length == 1);
require(EncodeDecode.encodeERC1155Id(
          assets[0].currencyId,
          assets[0].maturity,
	        assets[0].assetType
        == fCashID));

Note: This optimization can became invalid if an error message is added to require. Furthermore, consider using custom errors to save gas.