calculateAPY.js

const calculateAPY = async () => {
  try {
    //BLOCKS_PER_DAY varies acccording to network all values are approx and they keep changing
    //BLOCKS_PER_DAY = 21600 for Kovan Testnet
    //BLOCKS_PER_DAY = 28800 for BSC Testnet
    //BLOCKS_PER_DAY = 6400 for Ethereum Mainnet
    //I am using the value for Ethereum mainnet
    const BLOCKS_PER_YEAR = 6400 * 365;

    let rewardTokenPrice = 0;
    // For Price IN ETH
    // Reward Token is Dodgecoin in our case
    rewardTokenPrice = await getDogecoinPriceInETH();

    // For Price in BNB
    // If you want to do calculations in BNB uncomment line below and comment line number 13
    // rewardTokenPrice = await getDodgecoinPriceInBNB()

    // REWARD_PER_BLOCK = Number of tokens your farming contract gives out per block
    const REWARD_PER_BLOCK = 10000000000;
    const totalRewardPricePerYear = new BigNumber(rewardTokenPrice)
      .times(REWARD_PER_BLOCK)
      .times(BLOCKS_PER_YEAR);

    // Get Total LP Tokens Deposited in Farming Contract
    const LpTokenContract = new web3.eth.Contract(
      IUniswapV2Pair,
      LP_TOKEN_ADDRESS
    );

    const totalLpDepositedInFarmingContract = await LpTokenContract.methods
      .balanceOf(FARMING_CONTRACT_ADDRESS)
      .call();

    // Calculate LP Token Price
    const lpTokenPrice = await calculateLpTokenPrice();

    // Calculate Total Price Of LP Tokens in Contract
    const totalPriceOfLpTokensInFarmingContract = new BigNumber(
      lpTokenPrice
    ).times(totalLpDepositedInFarmingContract);

    // Calculate APY
    const apy = totalRewardPricePerYear
      .div(totalPriceOfLpTokensInFarmingContract)
      .times(100);

    // Return apy if apy is a valid number or return 0
    return apy.isNaN() || !apy.isFinite() ? 0 : apy.toNumber();

  } catch (e) {
    console.log(e);
    return 0;
  }
};