divide.js

"use strict";

const absolute = require("./absolute.js");
const clean = require("./clean.js");
const is_infinity = require("./is_infinity.js");
const long_division = require("./long_division.js");

/**
 * @name divide
 * @param {String} dividend
 * @param {String} divisor
 * @param {Object} options
 * @param {Number} options.max_decimal_digits
 * @param {Boolean} options.ellipsis
 * @returns {String} - quotient
 */
function divide(dividend, divisor, options) {
  dividend = clean(dividend);
  divisor = clean(divisor);

  const dividend_is_positive = dividend[0] !== "-";
  const divisor_is_positive = divisor[0] !== "-";

  const dividend_is_infinity = is_infinity(dividend);
  const divisor_is_infinity = is_infinity(divisor);

  if (dividend_is_infinity || divisor_is_infinity) {
    if (dividend_is_positive == divisor_is_positive) {
      return "Infinity";
    } else {
      return "-Infinity";
    }
  }

  if (divisor === "0") throw new Error("[preciso] division by zero");

  // sometimes dividend can be cleaned to ""
  if (dividend === "" || dividend === "0") return "0";

  const out_sign = dividend_is_positive !== divisor_is_positive ? "-" : "";

  if (!dividend_is_positive) dividend = absolute(dividend);
  if (!divisor_is_positive) divisor = absolute(divisor);

  return out_sign + long_division(dividend, divisor, options);
}

module.exports = divide;
module.exports.default = divide;