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luhn-generator

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A generator of numbers that passes the validation of Luhn algorithm or Luhn formula, also known as the 'modulus 10' or 'mod 10' algorithm

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var root = require('./_root'), toInteger = require('./toInteger'), toNumber = require('./toNumber'), toString = require('./toString'); /* 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); }; } module.exports = createRound;