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Updated luhn checksum to to work with base 2-36
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commit
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1 changed files with 36 additions and 17 deletions
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@ -1,5 +1,6 @@
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/**
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* @author n1073645 [n1073645@gmail.com]
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* @author n1073645 [n1073645@gmail.com]
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* @author k3ach [k3ach@proton.me]
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* @copyright Crown Copyright 2020
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* @license Apache-2.0
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*/
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@ -20,11 +21,17 @@ class LuhnChecksum extends Operation {
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this.name = "Luhn Checksum";
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this.module = "Default";
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this.description = "The Luhn algorithm, also known as the modulus 10 or mod 10 algorithm, is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers, IMEI numbers and Canadian Social Insurance Numbers.";
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this.infoURL = "https://wikipedia.org/wiki/Luhn_algorithm";
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this.description = "The Luhn mod N algorithm is an extension to the Luhn algorithm (also known as mod 10 algorithm) that allows it to work with sequences of values in any even-numbered base. This can be useful when a check digit is required to validate an identification string composed of letters, a combination of letters and digits or any arbitrary set of N characters where N is divisible by 2.";
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this.infoURL = "https://en.wikipedia.org/wiki/Luhn_mod_N_algorithm";
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this.inputType = "string";
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this.outputType = "string";
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this.args = [];
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this.args = [
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{
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"name": "Radix",
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"type": "number",
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"value": 10
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}
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];
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}
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/**
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@ -33,26 +40,27 @@ class LuhnChecksum extends Operation {
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* @param {string} inputStr
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* @returns {number}
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*/
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checksum(inputStr) {
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checksum(inputStr, radix = 10) {
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let even = false;
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return inputStr.split("").reverse().reduce((acc, elem) => {
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// Convert element to integer.
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let temp = parseInt(elem, 10);
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// Convert element to an integer based on the provided radix.
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let temp = parseInt(elem, radix);
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// If element is not an integer.
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if (isNaN(temp))
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throw new OperationError("Character: " + elem + " is not a digit.");
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// If element is not a valid number in the given radix.
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if (isNaN(temp)) {
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throw new Error("Character: " + elem + " is not valid in radix " + radix + ".");
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}
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// If element is in an even position
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if (even) {
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// Double the element and add the quotient and remainder together.
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temp = 2 * elem;
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temp = Math.floor(temp/10) + (temp % 10);
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// Double the element and sum the quotient and remainder.
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temp = 2 * temp;
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temp = Math.floor(temp / radix) + (temp % radix);
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}
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even = !even;
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return acc + temp;
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}, 0) % 10;
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}, 0) % radix; // Use radix as the modulus base
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}
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/**
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@ -63,9 +71,20 @@ class LuhnChecksum extends Operation {
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run(input, args) {
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if (!input) return "";
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const checkSum = this.checksum(input);
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let checkDigit = this.checksum(input + "0");
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checkDigit = checkDigit === 0 ? 0 : (10-checkDigit);
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let radix = args[0];
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if (radix < 2 || radix > 36) {
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throw new OperationError("Error: Radix argument must be between 2 and 36");
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}
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if (radix % 2 != 0) {
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throw new OperationError("Error: Radix argument must be divisible by 2");
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}
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const checkSum = this.checksum(input, radix).toString(radix);
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let checkDigit = this.checksum(input + "0", radix);
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checkDigit = checkDigit === 0 ? 0 : (radix - checkDigit);
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checkDigit = checkDigit.toString(radix)
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return `Checksum: ${checkSum}
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Checkdigit: ${checkDigit}
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