TokenAmount.parse doesn't work for decimal inputs without a whole number part

[ranger8888]

export const parseAmountFromString = <Tk extends Token<Tk>>(
  token: Tk,
  uiAmount: string
): JSBI => {
  const parts = uiAmount.split(".");
  if (parts.length === 0) {
    throw new Error("empty number");
  }
  invariant(parts[0]);
  const whole = JSBI.BigInt(parts[0]);

I believe this is in the @ubeswap/token-math package. Instead of using split, it may make sense to to just do a simple indexOf on the .