feat(isLocale): validate isLocale

- it validates different languages for different geographical location
- Closes #954

README.md

@@ -118,6 +118,7 @@ Validator                               | Description
 **isJWT(str)**                         | check if the string is valid JWT token.
 **isLatLong(str)**                      | check if the string is a valid latitude-longitude coordinate in the format `lat,long` or `lat, long`.
 **isLength(str [, options])**              | check if the string's length falls in a range.<br/><br/>`options` is an object which defaults to `{min:0, max: undefined}`. Note: this function takes into account surrogate pairs.
+**isLocale(str)**                       | check if the string is a locale
 **isLowercase(str)**                    | check if the string is lowercase.
 **isMACAddress(str)**                   | check if the string is a MAC address.<br/><br/>`options` is an object which defaults to `{no_colons: false}`. If `no_colons` is true, the validator will allow MAC addresses without the colons. Also, it allows the use of hyphens or spaces e.g  '01 02 03 04 05 ab' or '01-02-03-04-05-ab'. 
 **isMD5(str)**                          | check if the string is a MD5 hash.

index.js

@@ -33,6 +33,8 @@ var _isFQDN = _interopRequireDefault(require("./lib/isFQDN"));
 
 var _isBoolean = _interopRequireDefault(require("./lib/isBoolean"));
 
+var _isLocale = _interopRequireDefault(require("./lib/isLocale"));
+
 var _isAlpha = _interopRequireWildcard(require("./lib/isAlpha"));
 
 var _isAlphanumeric = _interopRequireWildcard(require("./lib/isAlphanumeric"));
@@ -203,6 +205,7 @@ var validator = {
   isJSON: _isJSON.default,
   isEmpty: _isEmpty.default,
   isLength: _isLength.default,
+  isLocale: _isLocale.default,
   isByteLength: _isByteLength.default,
   isUUID: _isUUID.default,
   isMongoId: _isMongoId.default,

lib/isLocale.js

@@ -0,0 +1,20 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = isLocale;
+
+var _assertString = _interopRequireDefault(require("./util/assertString"));
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+var localeReg = /^[A-z]{2,4}([_-]([A-z]{4}|[\d]{3}))?([_-]([A-z]{2}|[\d]{3}))?$/;
+
+function isLocale(str) {
+  (0, _assertString.default)(str);
+  return localeReg.test(str);
+}
+
+module.exports = exports.default;
+module.exports.default = exports.default;

src/index.js

@@ -14,6 +14,7 @@ import isIPRange from './lib/isIPRange';
 import isFQDN from './lib/isFQDN';
 
 import isBoolean from './lib/isBoolean';
+import isLocale from './lib/isLocale';
 
 import isAlpha, { locales as isAlphaLocales } from './lib/isAlpha';
 import isAlphanumeric, { locales as isAlphanumericLocales } from './lib/isAlphanumeric';
@@ -144,6 +145,7 @@ const validator = {
   isJSON,
   isEmpty,
   isLength,
+  isLocale,
   isByteLength,
   isUUID,
   isMongoId,

src/lib/isLocale.js

@@ -0,0 +1,8 @@
+import assertString from './util/assertString';
+
+const localeReg = /^[A-z]{2,4}([_-]([A-z]{4}|[\d]{3}))?([_-]([A-z]{2}|[\d]{3}))?$/;
+
+export default function isLocale(str) {
+  assertString(str);
+  return localeReg.test(str);
+}

test/validators.js

@@ -2801,6 +2801,25 @@ describe('Validators', () => {
     });
   });
 
+  it('should validate isLocale codes', () => {
+    test({
+      validator: 'isLocale',
+      valid: [
+        'uz_Latn_UZ',
+        'en',
+        'gsw',
+        'es_ES',
+        'sw_KE',
+        'am_ET',
+      ],
+      invalid: [
+        'lo_POP',
+        '12',
+        '12_DD',
+      ],
+    });
+  });
+
   it('should validate strings by byte length', () => {
     test({
       validator: 'isByteLength',

validator.js

@@ -665,6 +665,12 @@ function isBoolean(str) {
   return ['true', 'false', '1', '0'].indexOf(str) >= 0;
 }
 
+var localeReg = /^[A-z]{2,4}([_-]([A-z]{4}|[\d]{3}))?([_-]([A-z]{2}|[\d]{3}))?$/;
+function isLocale(str) {
+  assertString(str);
+  return localeReg.test(str);
+}
+
 var alpha = {
   'en-US': /^[A-Z]+$/i,
   'bg-BG': /^[А-Я]+$/i,
@@ -2072,6 +2078,7 @@ var validator = {
   isJSON: isJSON,
   isEmpty: isEmpty,
   isLength: isLength,
+  isLocale: isLocale,
   isByteLength: isByteLength,
   isUUID: isUUID,
   isMongoId: isMongoId,