import root from './_root.js'; import toInteger from './toInteger.js'; import toNumber from './toNumber.js'; import toString from './toString.js'; /* Built-in method references for those with the same name as other `lodash` methods. */ var nativeIsFinite = root.isFinite, nativeMin = Math.min; /** * Creates a function like `_.round`. * * @private * @param {string} methodName The name of the `Math` method to use when rounding. * @returns {Function} Returns the new round function. */ function createRound(methodName) { var func = Math[methodName]; return function(number, precision) { number = toNumber(number); precision = precision == null ? 0 : nativeMin(toInteger(precision), 292); if (precision && nativeIsFinite(number)) { // Shift with exponential notation to avoid floating-point issues. // See [MDN](https://mdn.io/round#Examples) for more details. var pair = (toString(number) + 'e').split('e'), value = func(pair[0] + 'e' + (+pair[1] + precision)); pair = (toString(value) + 'e').split('e'); return +(pair[0] + 'e' + (+pair[1] - precision)); } return func(number); }; } export default createRound;