check if Uniswap pair address exists

Question

I'd like to be able to check if an arbitrary address is a Uniswap liquidity pool pair address. I know I can compute the LP with CREATE2 but what if I don't know the tokens, I just have an address and want to know if it's a Uniswap LP. Will something like this work:

IUniswapV2Pair pair = IUniswapV2Pair(0x000...some address....0000);
uint256 price=pair.price0CumulativeLast();
if (price>0) { this is a real LP... }

Or is there a Uniswap function specifically for this purpose?

Answer 1

Actually, you can try to call any function of possible pair contract

contract PairChecker {
    function _tryPairTokens(address token, address possiblyPair)
        public
        view
        returns (bool isPair)
    {
        address token0 = IUniswapV2Pair(possiblyPair).token0();
        address token1 = IUniswapV2Pair(possiblyPair).token1();
        return token0 == token || token1 == token;
    }

    function _checkPair(address token, address possiblyPair)
        internal
        view
        returns (bool isPair)
    {
        try this._tryPairTokens(token, possiblyPair) returns (bool value) {
            if (token == address(0)) return true;
            return value;
        } catch {
            return false;
        }
    }
}

Just call _tryPairTokens(token, possiblePair) to figure out if address is pair of your token or not. Same stuff you can do without having a token