calculateRatioAmountIn() throws an Error when the optimalRatio is zero. about smart-order-router

[hensha256]

#65 seems to be a duplicate of this. This issue has more details so I closed the other, but it is there if we want to reference another issue.

[hiroshitashir]

I believe this bug is fixed in the current version 3.2.6.

In Fraction.constructor, numerator and denominator are always initialized.

  public constructor(numerator: BigintIsh, denominator: BigintIsh = JSBI.BigInt(1)) {
    this.numerator = JSBI.BigInt(numerator)
    this.denominator = JSBI.BigInt(denominator)
  }

In Fraction.tryParseFraction, new Fraction(fractionish) is created when type of fractionish is BigintIsh (or instance of JSBI, number or string).

  private static tryParseFraction(fractionish: BigintIsh | Fraction): Fraction {
    if (fractionish instanceof JSBI || typeof fractionish === 'number' || typeof fractionish === 'string')
      return new Fraction(fractionish)

    if ('numerator' in fractionish && 'denominator' in fractionish) return fractionish
    throw new Error('Could not parse fraction')
  }

Finally, when fractionish is CurrencyAmount, CurrencyAmount.constructor always calls Fraction.constructor with super(numerator, denominator), which means numerator and denominator are always initialized.

  protected constructor(currency: T, numerator: BigintIsh, denominator?: BigintIsh) {
    super(numerator, denominator)
    invariant(JSBI.lessThanOrEqual(this.quotient, MaxUint256), 'AMOUNT')
    this.currency = currency
    this.decimalScale = JSBI.exponentiate(JSBI.BigInt(10), JSBI.BigInt(currency.decimals))
  }