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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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'use strict'; var $ = require('../internals/export'); var toAbsoluteIndex = require('../internals/to-absolute-index'); var toInteger = require('../internals/to-integer'); var toLength = require('../internals/to-length'); var toObject = require('../internals/to-object'); var arraySpeciesCreate = require('../internals/array-species-create'); var createProperty = require('../internals/create-property'); var arrayMethodHasSpeciesSupport = require('../internals/array-method-has-species-support'); var arrayMethodUsesToLength = require('../internals/array-method-uses-to-length'); var HAS_SPECIES_SUPPORT = arrayMethodHasSpeciesSupport('splice'); var USES_TO_LENGTH = arrayMethodUsesToLength('splice', { ACCESSORS: true, 0: 0, 1: 2 }); var max = Math.max; var min = Math.min; var MAX_SAFE_INTEGER = 0x1FFFFFFFFFFFFF; var MAXIMUM_ALLOWED_LENGTH_EXCEEDED = 'Maximum allowed length exceeded'; // `Array.prototype.splice` method // https://tc39.github.io/ecma262/#sec-array.prototype.splice // with adding support of @@species $({ target: 'Array', proto: true, forced: !HAS_SPECIES_SUPPORT || !USES_TO_LENGTH }, { splice: function splice(start, deleteCount /* , ...items */) { var O = toObject(this); var len = toLength(O.length); var actualStart = toAbsoluteIndex(start, len); var argumentsLength = arguments.length; var insertCount, actualDeleteCount, A, k, from, to; if (argumentsLength === 0) { insertCount = actualDeleteCount = 0; } else if (argumentsLength === 1) { insertCount = 0; actualDeleteCount = len - actualStart; } else { insertCount = argumentsLength - 2; actualDeleteCount = min(max(toInteger(deleteCount), 0), len - actualStart); } if (len + insertCount - actualDeleteCount > MAX_SAFE_INTEGER) { throw TypeError(MAXIMUM_ALLOWED_LENGTH_EXCEEDED); } A = arraySpeciesCreate(O, actualDeleteCount); for (k = 0; k < actualDeleteCount; k++) { from = actualStart + k; if (from in O) createProperty(A, k, O[from]); } A.length = actualDeleteCount; if (insertCount < actualDeleteCount) { for (k = actualStart; k < len - actualDeleteCount; k++) { from = k + actualDeleteCount; to = k + insertCount; if (from in O) O[to] = O[from]; else delete O[to]; } for (k = len; k > len - actualDeleteCount + insertCount; k--) delete O[k - 1]; } else if (insertCount > actualDeleteCount) { for (k = len - actualDeleteCount; k > actualStart; k--) { from = k + actualDeleteCount - 1; to = k + insertCount - 1; if (from in O) O[to] = O[from]; else delete O[to]; } } for (k = 0; k < insertCount; k++) { O[k + actualStart] = arguments[k + 2]; } O.length = len - actualDeleteCount + insertCount; return A; } });