ConstantProductCurve output ts vs anchor code

[EmilRejman]

in typescript implementation fo ConstantProductCurve swapWithoutFees gives different output then one in rust/anchor

ts implementation:

static swapWithoutFees(sourceAmount: BN, swapSourceAmount: BN, swapDestinationAmount: BN): SwapWithoutFeesResult {
    const invariant = swapSourceAmount.mul(swapDestinationAmount);

    const newSwapSourceAmount = swapSourceAmount.add(sourceAmount);
    const [newSwapDestinationAmount, _newSwapSourceAmount] = checkedCeilDiv(invariant, newSwapSourceAmount);

    const sourceAmountSwapped = _newSwapSourceAmount.sub(swapSourceAmount);
    const destinationAmountSwapped = swapDestinationAmount.sub(newSwapDestinationAmount);
    if (destinationAmountSwapped.isZero()) throw Error("destinationAmountSwapped is zero");

    return {
      sourceAmountSwapped,
      destinationAmountSwapped,
    };
  }

rust/anchor:

  pub fn swap_base_input_without_fees(
        source_amount: u128,
        swap_source_amount: u128,
        swap_destination_amount: u128,
    ) -> u128 {
        // (x + delta_x) * (y - delta_y) = x * y
        // delta_y = (delta_x * y) / (x + delta_x)
        let numerator = source_amount.checked_mul(swap_destination_amount).unwrap();
        let denominator = swap_source_amount.checked_add(source_amount).unwrap();
        let destinsation_amount_swapped = numerator.checked_div(denominator).unwrap();
        destinsation_amount_swapped
    }

They give different amounts of destinationAmountSwapped.