PHP's round in JavaScript

functionroundToInt (value, mode) {
let tmp = Math.floor(Math.abs(value) + 0.5)
if (
    (mode === 'PHP_ROUND_HALF_DOWN' && value === (tmp - 0.5)) ||
      (mode === 'PHP_ROUND_HALF_EVEN' && value === (0.5 + 2 * Math.floor(tmp / 2))) ||
      (mode === 'PHP_ROUND_HALF_ODD' && value === (0.5 + 2 * Math.floor(tmp / 2) - 1))) {
    tmp -= 1
  }
return value < 0 ? -tmp : tmp
}
module.exports = functionround (value, precision = 0, mode = 'PHP_ROUND_HALF_UP') {
//  discuss at: https://locutus.io/php/round/
// original by: Philip Peterson
//  revised by: Onno Marsman (https://twitter.com/onnomarsman)
//  revised by: T.Wild
//  revised by: Rafał Kukawski (https://blog.kukawski.pl)
//    input by: Greenseed
//    input by: meo
//    input by: William
//    input by: Josep Sanz (https://www.ws3.es/)
// bugfixed by: Brett Zamir (https://brett-zamir.me)
//  revised by: Rafał Kukawski
//   example 1: round(1241757, -3)
//   returns 1: 1242000
//   example 2: round(3.6)
//   returns 2: 4
//   example 3: round(2.835, 2)
//   returns 3: 2.84
//   example 4: round(1.1749999999999, 2)
//   returns 4: 1.17
//   example 5: round(58551.799999999996, 2)
//   returns 5: 58551.8
//   example 6: round(4096.485, 2)
//   returns 6: 4096.49
const floatCast = require('../_helpers/_php_cast_float')
const intCast = require('../_helpers/_php_cast_int')
let p
// the code is heavily based on the native PHP implementation
// https://github.com/php/php-src/blob/PHP-7.4/ext/standard/math.c#L355
  value = floatCast(value)
  precision = intCast(precision)
  p = Math.pow(10, precision)
if (isNaN(value) || !isFinite(value)) {
return value
  }
// if value already integer and positive precision
// then nothing to do, return early
if (Math.trunc(value) === value && precision >= 0) {
return value
  }
// PHP does a pre-rounding before rounding to desired precision
// https://wiki.php.net/rfc/rounding#pre-rounding_to_the_value_s_precision_if_possible
const preRoundPrecision = 14 - Math.floor(Math.log10(Math.abs(value)))
if (preRoundPrecision > precision && preRoundPrecision - 15 < precision) {
    value = roundToInt(value * Math.pow(10, preRoundPrecision), mode)
    value /= Math.pow(10, Math.abs(precision - preRoundPrecision))
  } else {
    value *= p
  }
  value = roundToInt(value, mode)
return value / p
}