mev-inspect/lib/utils.js

A JS port of 'mev-inspect-py' optimised for ease of use.

function getBlock(mev) {
    return getEvent(mev)?.block || null;
}
function getTransaction(mev) {
    return getEvent(mev)?.transaction || null;
}
function getEvent(mev) {
    if (isArbitrage(mev)) {
        const arbitrage = mev;
        if (arbitrage.swaps.length === 0) {
            return null;
        }
        return arbitrage.swaps[0];
    }
    if (isLiquidation(mev)) {
        const liquidation = mev;
        return liquidation.repayment;
    }
    if (isSandwich(mev)) {
        const sandwich = mev;
        return sandwich.frontSwap;
    }
    return null;
}
function isArbitrage(mev) {
    return ('arbitrager' in mev &&
        mev.swaps.every((swap) => swap.assetIn.type === 'erc20' && swap.assetOut.type === 'erc20'));
}
function isLiquidation(mev) {
    return 'liquidator' in mev;
}
function isSandwich(mev) {
    return 'frontSwap' in mev;
}
function isJitSandwich(mev) {
    return 'deposit' in mev;
}
function isNftArbitrage(mev) {
    return ('arbitrager' in mev &&
        mev.swaps.some((swap) => swap.assetIn.type === 'erc721' || swap.assetOut.type === 'erc721'));
}
function getArbitrages(mevList) {
    return mevList.filter((mev) => isArbitrage(mev));
}
function getLiquidations(mevList) {
    return mevList.filter((mev) => isLiquidation(mev));
}
function getSandwiches(mevList) {
    return mevList.filter((mev) => isSandwich(mev));
}
function getJitSandwiches(mevList) {
    return mevList.filter((mev) => isJitSandwich(mev));
}
function getNftArbitrages(mevList) {
    return mevList.filter((mev) => isNftArbitrage(mev));
}
function equalWithTolerance(firstValue, secondValue, threshold) {
    // Special case: either of values is zero
    if (firstValue === 0n || secondValue === 0n) {
        if (firstValue === 0n && secondValue === 0n) {
            return true;
        }
        if (firstValue === 0n) {
            return false;
        }
        return threshold >= 1;
    }
    // Should be of the same sign
    if (firstValue > 0 !== secondValue > 0) {
        return false;
    }
    // Compare in absolute values
    if (firstValue < 0n) {
        firstValue = -firstValue;
        secondValue = -secondValue;
    }
    // a * (1 + threshold) >= b >= a * (1 - threshold)
    const divisionMultiplier = 1000000000n;
    const thresholdMultiplier = Number(divisionMultiplier);
    const rate = (divisionMultiplier * secondValue) / firstValue;
    const isWithinLowerBound = threshold * thresholdMultiplier >= rate - divisionMultiplier;
    const isWithinHigherBound = threshold * thresholdMultiplier >= divisionMultiplier - rate;
    return isWithinLowerBound && isWithinHigherBound;
}
function minByAbs(a, b) {
    const absA = a > 0 ? a : -a;
    const absB = b > 0 ? b : -b;
    return absA < absB ? a : b;
}
function groupBy(arr, filter) {
    const grouped = {};
    for (const item of arr) {
        const key = filter(item);
        if (!grouped[key]) {
            grouped[key] = [];
        }
        grouped[key].push(item);
    }
    return grouped;
}
export { equalWithTolerance, getArbitrages, getBlock, getJitSandwiches, getLiquidations, getNftArbitrages, getSandwiches, getTransaction, groupBy, isArbitrage, isLiquidation, isSandwich, isJitSandwich, isNftArbitrage, minByAbs, };
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