1var root = require('./_root'),
2    toInteger = require('./toInteger'),
3    toNumber = require('./toNumber'),
4    toString = require('./toString');
5
6/* Built-in method references for those with the same name as other `lodash` methods. */
7var nativeIsFinite = root.isFinite,
8    nativeMin = Math.min;
9
10/**
11 * Creates a function like `_.round`.
12 *
13 * @private
14 * @param {string} methodName The name of the `Math` method to use when rounding.
15 * @returns {Function} Returns the new round function.
16 */
17function createRound(methodName) {
18  var func = Math[methodName];
19  return function(number, precision) {
20    number = toNumber(number);
21    precision = precision == null ? 0 : nativeMin(toInteger(precision), 292);
22    if (precision && nativeIsFinite(number)) {
23      // Shift with exponential notation to avoid floating-point issues.
24      // See [MDN](https://mdn.io/round#Examples) for more details.
25      var pair = (toString(number) + 'e').split('e'),
26          value = func(pair[0] + 'e' + (+pair[1] + precision));
27
28      pair = (toString(value) + 'e').split('e');
29      return +(pair[0] + 'e' + (+pair[1] - precision));
30    }
31    return func(number);
32  };
33}
34
35module.exports = createRound;
36