Gas Optimization: Duplicated checks

[code423n4]

Handle

gzeon

Vulnerability details

Impact

swapBaseTokenForQuoteToken check for _baseTokenQty > 0 && _minQuoteTokenQty > 0, but the same check also exists next line in MathLib.calculateQuoteTokenQty

Proof of Concept

https://github.com/code-423n4/2022-01-elasticswap/blob/d107a198c0d10fbe254d69ffe5be3e40894ff078/elasticswap/src/contracts/Exchange.sol#L260

    function swapBaseTokenForQuoteToken(
        uint256 _baseTokenQty,
        uint256 _minQuoteTokenQty,
        uint256 _expirationTimestamp
    ) external nonReentrant() {
        isNotExpired(_expirationTimestamp);
        require(
            _baseTokenQty > 0 && _minQuoteTokenQty > 0,
            "Exchange: INSUFFICIENT_TOKEN_QTY"
        );

        uint256 quoteTokenQty =
            MathLib.calculateQuoteTokenQty(
                _baseTokenQty,
                _minQuoteTokenQty,
                TOTAL_LIQUIDITY_FEE,
                internalBalances
            );

https://github.com/code-423n4/2022-01-elasticswap/blob/d107a198c0d10fbe254d69ffe5be3e40894ff078/elasticswap/src/libraries/MathLib.sol#L664

    function calculateQuoteTokenQty(
        uint256 _baseTokenQty,
        uint256 _quoteTokenQtyMin,
        uint256 _liquidityFeeInBasisPoints,
        InternalBalances storage _internalBalances
    ) public returns (uint256 quoteTokenQty) {
        require(
            _baseTokenQty > 0 && _quoteTokenQtyMin > 0,
            "MathLib: INSUFFICIENT_TOKEN_QTY"
        );

[GalloDaSballo]

Duplicate of #173