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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 token = '%[a-f0-9]{2}'; var singleMatcher = new RegExp(token, 'gi'); var multiMatcher = new RegExp('(' + token + ')+', 'gi'); function decodeComponents(components, split) { try { // Try to decode the entire string first return decodeURIComponent(components.join('')); } catch (err) { // Do nothing } if (components.length === 1) { return components; } split = split || 1; // Split the array in 2 parts var left = components.slice(0, split); var right = components.slice(split); return Array.prototype.concat.call([], decodeComponents(left), decodeComponents(right)); } function decode(input) { try { return decodeURIComponent(input); } catch (err) { var tokens = input.match(singleMatcher); for (var i = 1; i < tokens.length; i++) { input = decodeComponents(tokens, i).join(''); tokens = input.match(singleMatcher); } return input; } } function customDecodeURIComponent(input) { // Keep track of all the replacements and prefill the map with the `BOM` var replaceMap = { '%FE%FF': '\uFFFD\uFFFD', '%FF%FE': '\uFFFD\uFFFD' }; var match = multiMatcher.exec(input); while (match) { try { // Decode as big chunks as possible replaceMap[match[0]] = decodeURIComponent(match[0]); } catch (err) { var result = decode(match[0]); if (result !== match[0]) { replaceMap[match[0]] = result; } } match = multiMatcher.exec(input); } // Add `%C2` at the end of the map to make sure it does not replace the combinator before everything else replaceMap['%C2'] = '\uFFFD'; var entries = Object.keys(replaceMap); for (var i = 0; i < entries.length; i++) { // Replace all decoded components var key = entries[i]; input = input.replace(new RegExp(key, 'g'), replaceMap[key]); } return input; } module.exports = function (encodedURI) { if (typeof encodedURI !== 'string') { throw new TypeError('Expected `encodedURI` to be of type `string`, got `' + typeof encodedURI + '`'); } try { encodedURI = encodedURI.replace(/\+/g, ' '); // Try the built in decoder first return decodeURIComponent(encodedURI); } catch (err) { // Fallback to a more advanced decoder return customDecodeURIComponent(encodedURI); } };