Uniswap
Improving computation of amountUSD.
The currently computed amountUSD of a swap is sometimes wrong, Sometimes the resulting output is 0, and sometimes it is divided by 2 when it shouldn't.
USD prices are computed in src/utils/pricing.ts this way:
let price0USD = token0.derivedETH.times(bundle.ethPriceUSD)
let price1USD = token1.derivedETH.times(bundle.ethPriceUSD)
When both tokens are whitelisted both amounts are supposed to be non-zero. However, sometimes the computed one of both outputs price{0-1}USD is 0, either because token0.derivedETH is 0 or bundle.ethPriceUSD is zero. ( I didn't find the root cause of the issue ). In this case, when computing the amount USD price, when both tokens are whitelisted, you could avoid returning the wrong price in
// both are whitelist tokens, return sum of both amounts
if (WHITELIST_TOKENS.includes(token0.id) && WHITELIST_TOKENS.includes(token1.id)) {
return tokenAmount0.times(price0USD).plus(tokenAmount1.times(price1USD))
}
By first checking if one of both price{0-1}USD is 0. If this is the case you should return the non-zero prices multiplied by 2, instead of returning one of the two prices + 0. Otherwise, it will wrongly be divided by 2 when calling the function.
In the other cases when only one of both tokens is whitelisted sometimes a price of 0 is returned. I am not sure where this issue comes from ...
