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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

129 lines (111 loc) 4.42 kB
'use strict'; var GetIntrinsic = require('../GetIntrinsic'); var $TypeError = GetIntrinsic('%TypeError%'); var callBound = require('../helpers/callBound'); var regexTester = require('../helpers/regexTester'); var every = require('../helpers/every'); var $charAt = callBound('String.prototype.charAt'); var $strSlice = callBound('String.prototype.slice'); var $indexOf = callBound('String.prototype.indexOf'); var $parseInt = parseInt; var isDigit = regexTester(/^[0-9]$/); var inspect = require('object-inspect'); var Get = require('./Get'); var IsArray = require('./IsArray'); var IsInteger = require('./IsInteger'); var ToObject = require('./ToObject'); var ToString = require('./ToString'); var Type = require('./Type'); var canDistinguishSparseFromUndefined = 0 in [undefined]; // IE 6 - 8 have a bug where this returns false var isStringOrHole = function (capture, index, arr) { return Type(capture) === 'String' || (canDistinguishSparseFromUndefined ? !(index in arr) : Type(capture) === 'Undefined'); }; // http://www.ecma-international.org/ecma-262/9.0/#sec-getsubstitution // eslint-disable-next-line max-statements, max-params, max-lines-per-function module.exports = function GetSubstitution(matched, str, position, captures, namedCaptures, replacement) { if (Type(matched) !== 'String') { throw new $TypeError('Assertion failed: `matched` must be a String'); } var matchLength = matched.length; if (Type(str) !== 'String') { throw new $TypeError('Assertion failed: `str` must be a String'); } var stringLength = str.length; if (!IsInteger(position) || position < 0 || position > stringLength) { throw new $TypeError('Assertion failed: `position` must be a nonnegative integer, and less than or equal to the length of `string`, got ' + inspect(position)); } if (!IsArray(captures) || !every(captures, isStringOrHole)) { throw new $TypeError('Assertion failed: `captures` must be a List of Strings, got ' + inspect(captures)); } if (Type(replacement) !== 'String') { throw new $TypeError('Assertion failed: `replacement` must be a String'); } var tailPos = position + matchLength; var m = captures.length; if (Type(namedCaptures) !== 'Undefined') { namedCaptures = ToObject(namedCaptures); // eslint-disable-line no-param-reassign } var result = ''; for (var i = 0; i < replacement.length; i += 1) { // if this is a $, and it's not the end of the replacement var current = $charAt(replacement, i); var isLast = (i + 1) >= replacement.length; var nextIsLast = (i + 2) >= replacement.length; if (current === '$' && !isLast) { var next = $charAt(replacement, i + 1); if (next === '$') { result += '$'; i += 1; } else if (next === '&') { result += matched; i += 1; } else if (next === '`') { result += position === 0 ? '' : $strSlice(str, 0, position - 1); i += 1; } else if (next === "'") { result += tailPos >= stringLength ? '' : $strSlice(str, tailPos); i += 1; } else { var nextNext = nextIsLast ? null : $charAt(replacement, i + 2); if (isDigit(next) && next !== '0' && (nextIsLast || !isDigit(nextNext))) { // $1 through $9, and not followed by a digit var n = $parseInt(next, 10); // if (n > m, impl-defined) result += (n <= m && Type(captures[n - 1]) === 'Undefined') ? '' : captures[n - 1]; i += 1; } else if (isDigit(next) && (nextIsLast || isDigit(nextNext))) { // $00 through $99 var nn = next + nextNext; var nnI = $parseInt(nn, 10) - 1; // if nn === '00' or nn > m, impl-defined result += (nn <= m && Type(captures[nnI]) === 'Undefined') ? '' : captures[nnI]; i += 2; } else if (next === '<') { // eslint-disable-next-line max-depth if (Type(namedCaptures) === 'Undefined') { result += '$<'; i += 2; } else { var endIndex = $indexOf(replacement, '>', i); // eslint-disable-next-line max-depth if (endIndex > -1) { var groupName = $strSlice(replacement, i, endIndex); var capture = Get(namedCaptures, groupName); // eslint-disable-next-line max-depth if (Type(capture) !== 'Undefined') { result += ToString(capture); } i += '$<' + groupName + '>'.length; } } } else { result += '$'; } } } else { // the final $, or else not a $ result += $charAt(replacement, i); } } return result; };