Create isISO6391.ts

Author: RobinvanderVliet

src/decorator/string/isISO6391.ts

@@ -0,0 +1,31 @@
+import { ValidationOptions } from '../ValidationOptions';
+import { buildMessage, ValidateBy } from '../common/ValidateBy';
+import isISO6391Validator from 'validator/lib/isISO6391';
+
+export const IS_ISO6391 = 'isISO6391';
+
+/**
+ * Check if the string is a valid [ISO 639-1](https://en.wikipedia.org/wiki/ISO_639-1) officially assigned language code.
+ */
+export function isISO6391(value: unknown): boolean {
+  return typeof value === 'string' && isISO6391Validator(value);
+}
+
+/**
+ * Check if the string is a valid [ISO 639-1](https://en.wikipedia.org/wiki/ISO_639-1) officially assigned language code.
+ */
+export function IsISO6391(validationOptions?: ValidationOptions): PropertyDecorator {
+  return ValidateBy(
+    {
+      name: IS_ISO6391,
+      validator: {
+        validate: (value, args): boolean => isISO6391(value),
+        defaultMessage: buildMessage(
+          eachPrefix => eachPrefix + '$property must be a valid ISO 639-1 language code',
+          validationOptions
+        ),
+      },
+    },
+    validationOptions
+  );
+}