feat(isEAN): implement isEAN validator (#1244)

* feat(isEAN): implement isEAN validator

* add testcase to cover 0 as EAN check digit

* modify EAN regex to avoid lookbehind assertions

README.md

@@ -114,6 +114,7 @@ Validator                               | Description
 **isIP(str [, version])**               | check if the string is an IP (version 4 or 6).
 **isIPRange(str)**                      | check if the string is an IP Range(version 4 only).
 **isISBN(str [, version])**             | check if the string is an ISBN (version 10 or 13).
+**isEAN(str)**                          | check if the string is an EAN (European Article Number).
 **isISIN(str)**                         | check if the string is an [ISIN][ISIN] (stock/security identifier).
 **isISO31661Alpha2(str)**               | check if the string is a valid [ISO 3166-1 alpha-2](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2) officially assigned country code.
 **isISO31661Alpha3(str)**               | check if the string is a valid [ISO 3166-1 alpha-3](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-3) officially assigned country code.

index.js

@@ -107,6 +107,8 @@ var _isCreditCard = _interopRequireDefault(require("./lib/isCreditCard"));
 
 var _isIdentityCard = _interopRequireDefault(require("./lib/isIdentityCard"));
 
+var _isEAN = _interopRequireDefault(require("./lib/isEAN"));
+
 var _isISIN = _interopRequireDefault(require("./lib/isISIN"));
 
 var _isISBN = _interopRequireDefault(require("./lib/isISBN"));
@@ -225,6 +227,7 @@ var validator = {
   isIn: _isIn.default,
   isCreditCard: _isCreditCard.default,
   isIdentityCard: _isIdentityCard.default,
+  isEAN: _isEAN.default,
   isISIN: _isISIN.default,
   isISBN: _isISBN.default,
   isISSN: _isISSN.default,

lib/isEAN.js

@@ -0,0 +1,80 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = isEAN;
+
+var _assertString = _interopRequireDefault(require("./util/assertString"));
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+/**
+ * The most commonly used EAN standard is
+ * the thirteen-digit EAN-13, while the
+ * less commonly used 8-digit EAN-8 barcode was
+ * introduced for use on small packages.
+ * EAN consists of:
+ * GS1 prefix, manufacturer code, product code and check digit
+ * Reference: https://en.wikipedia.org/wiki/International_Article_Number
+ */
+
+/**
+ * Define EAN Lenghts; 8 for EAN-8; 13 for EAN-13
+ * and Regular Expression for valid EANs (EAN-8, EAN-13),
+ * with exact numberic matching of 8 or 13 digits [0-9]
+ */
+var LENGTH_EAN_8 = 8;
+var validEanRegex = /^(\d{8}|\d{13})$/;
+/**
+ * Get position weight given:
+ * EAN length and digit index/position
+ *
+ * @param {number} length
+ * @param {number} index
+ * @return {number}
+ */
+
+function getPositionWeightThroughLengthAndIndex(length, index) {
+  if (length === LENGTH_EAN_8) {
+    return index % 2 === 0 ? 3 : 1;
+  }
+
+  return index % 2 === 0 ? 1 : 3;
+}
+/**
+ * Calculate EAN Check Digit
+ * Reference: https://en.wikipedia.org/wiki/International_Article_Number#Calculation_of_checksum_digit
+ *
+ * @param {string} ean
+ * @return {number}
+ */
+
+
+function calculateCheckDigit(ean) {
+  var checksum = ean.slice(0, -1).split('').map(function (char, index) {
+    return Number(char) * getPositionWeightThroughLengthAndIndex(ean.length, index);
+  }).reduce(function (acc, partialSum) {
+    return acc + partialSum;
+  }, 0);
+  var remainder = 10 - checksum % 10;
+  return remainder < 10 ? remainder : 0;
+}
+/**
+ * Check if string is valid EAN:
+ * Matches EAN-8/EAN-13 regex
+ * Has valid check digit.
+ *
+ * @param {string} str
+ * @return {boolean}
+ */
+
+
+function isEAN(str) {
+  (0, _assertString.default)(str);
+  var actualCheckDigit = Number(str.slice(-1));
+  return validEanRegex.test(str) && actualCheckDigit === calculateCheckDigit(str);
+}
+
+module.exports = exports.default;
+module.exports.default = exports.default;

src/index.js

@@ -64,6 +64,7 @@ import isIn from './lib/isIn';
 import isCreditCard from './lib/isCreditCard';
 import isIdentityCard from './lib/isIdentityCard';
 
+import isEAN from './lib/isEAN';
 import isISIN from './lib/isISIN';
 import isISBN from './lib/isISBN';
 import isISSN from './lib/isISSN';
@@ -160,6 +161,7 @@ const validator = {
   isIn,
   isCreditCard,
   isIdentityCard,
+  isEAN,
   isISIN,
   isISBN,
   isISSN,

src/lib/isEAN.js

@@ -0,0 +1,70 @@
+/**
+ * The most commonly used EAN standard is
+ * the thirteen-digit EAN-13, while the
+ * less commonly used 8-digit EAN-8 barcode was
+ * introduced for use on small packages.
+ * EAN consists of:
+ * GS1 prefix, manufacturer code, product code and check digit
+ * Reference: https://en.wikipedia.org/wiki/International_Article_Number
+ */
+
+import assertString from './util/assertString';
+
+/**
+ * Define EAN Lenghts; 8 for EAN-8; 13 for EAN-13
+ * and Regular Expression for valid EANs (EAN-8, EAN-13),
+ * with exact numberic matching of 8 or 13 digits [0-9]
+ */
+const LENGTH_EAN_8 = 8;
+const validEanRegex = /^(\d{8}|\d{13})$/;
+
+
+/**
+ * Get position weight given:
+ * EAN length and digit index/position
+ *
+ * @param {number} length
+ * @param {number} index
+ * @return {number}
+ */
+function getPositionWeightThroughLengthAndIndex(length, index) {
+  if (length === LENGTH_EAN_8) {
+    return (index % 2 === 0) ? 3 : 1;
+  }
+
+  return (index % 2 === 0) ? 1 : 3;
+}
+
+/**
+ * Calculate EAN Check Digit
+ * Reference: https://en.wikipedia.org/wiki/International_Article_Number#Calculation_of_checksum_digit
+ *
+ * @param {string} ean
+ * @return {number}
+ */
+function calculateCheckDigit(ean) {
+  const checksum = ean
+    .slice(0, -1)
+    .split('')
+    .map((char, index) => Number(char) * getPositionWeightThroughLengthAndIndex(ean.length, index))
+    .reduce((acc, partialSum) => acc + partialSum, 0);
+
+  const remainder = 10 - (checksum % 10);
+
+  return remainder < 10 ? remainder : 0;
+}
+
+/**
+ * Check if string is valid EAN:
+ * Matches EAN-8/EAN-13 regex
+ * Has valid check digit.
+ *
+ * @param {string} str
+ * @return {boolean}
+ */
+export default function isEAN(str) {
+  assertString(str);
+  const actualCheckDigit = Number(str.slice(-1));
+
+  return validEanRegex.test(str) && actualCheckDigit === calculateCheckDigit(str);
+}

test/validators.js

@@ -3475,6 +3475,25 @@ describe('Validators', () => {
     });
   });
 
+  it('should validate EANs', () => {
+    test({
+      validator: 'isEAN',
+      valid: [
+        '9421023610112',
+        '1234567890128',
+        '4012345678901',
+        '9771234567003',
+        '9783161484100',
+        '73513537',
+      ],
+      invalid: [
+        '5901234123451',
+        '079777681629',
+        '0705632085948',
+      ],
+    });
+  });
+
   it('should validate ISSNs', () => {
     test({
       validator: 'isISSN',

validator.js

@@ -27,8 +27,6 @@
 }(this, (function () { 'use strict';
 
 function _typeof(obj) {
-  "@babel/helpers - typeof";
-
   if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") {
     _typeof = function (obj) {
       return typeof obj;
@@ -1446,6 +1444,73 @@ function isIdentityCard(str, locale) {
   throw new Error("Invalid locale '".concat(locale, "'"));
 }
 
+/**
+ * The most commonly used EAN standard is
+ * the thirteen-digit EAN-13, while the
+ * less commonly used 8-digit EAN-8 barcode was
+ * introduced for use on small packages.
+ * EAN consists of:
+ * GS1 prefix, manufacturer code, product code and check digit
+ * Reference: https://en.wikipedia.org/wiki/International_Article_Number
+ */
+/**
+ * Define EAN Lenghts; 8 for EAN-8; 13 for EAN-13
+ * and Regular Expression for valid EANs (EAN-8, EAN-13),
+ * with exact numberic matching of 8 or 13 digits [0-9]
+ */
+
+var LENGTH_EAN_8 = 8;
+var validEanRegex = /^(\d{8}|\d{13})$/;
+/**
+ * Get position weight given:
+ * EAN length and digit index/position
+ *
+ * @param {number} length
+ * @param {number} index
+ * @return {number}
+ */
+
+function getPositionWeightThroughLengthAndIndex(length, index) {
+  if (length === LENGTH_EAN_8) {
+    return index % 2 === 0 ? 3 : 1;
+  }
+
+  return index % 2 === 0 ? 1 : 3;
+}
+/**
+ * Calculate EAN Check Digit
+ * Reference: https://en.wikipedia.org/wiki/International_Article_Number#Calculation_of_checksum_digit
+ *
+ * @param {string} ean
+ * @return {number}
+ */
+
+
+function calculateCheckDigit(ean) {
+  var checksum = ean.slice(0, -1).split('').map(function (_char, index) {
+    return Number(_char) * getPositionWeightThroughLengthAndIndex(ean.length, index);
+  }).reduce(function (acc, partialSum) {
+    return acc + partialSum;
+  }, 0);
+  var remainder = 10 - checksum % 10;
+  return remainder < 10 ? remainder : 0;
+}
+/**
+ * Check if string is valid EAN:
+ * Matches EAN-8/EAN-13 regex
+ * Has valid check digit.
+ *
+ * @param {string} str
+ * @return {boolean}
+ */
+
+
+function isEAN(str) {
+  assertString(str);
+  var actualCheckDigit = Number(str.slice(-1));
+  return validEanRegex.test(str) && actualCheckDigit === calculateCheckDigit(str);
+}
+
 var isin = /^[A-Z]{2}[0-9A-Z]{9}[0-9]$/;
 function isISIN(str) {
   assertString(str);
@@ -2313,6 +2378,7 @@ var validator = {
   isIn: isIn,
   isCreditCard: isCreditCard,
   isIdentityCard: isIdentityCard,
+  isEAN: isEAN,
   isISIN: isISIN,
   isISBN: isISBN,
   isISSN: isISSN,