add isBase58 functionality

README.md

@@ -88,6 +88,7 @@ Validator                               | Description
 **isAlphanumeric(str [, locale])**      | check if the string contains only letters and numbers.<br/><br/>Locale is one of `['ar', 'ar-AE', 'ar-BH', 'ar-DZ', 'ar-EG', 'ar-IQ', 'ar-JO', 'ar-KW', 'ar-LB', 'ar-LY', 'ar-MA', 'ar-QA', 'ar-QM', 'ar-SA', 'ar-SD', 'ar-SY', 'ar-TN', 'ar-YE', 'bg-BG', 'cs-CZ', 'da-DK', 'de-DE', 'el-GR', 'en-AU', 'en-GB', 'en-HK', 'en-IN', 'en-NZ', 'en-US', 'en-ZA', 'en-ZM', 'es-ES', 'fr-FR', 'fa', 'fa-AF', 'fa-IR', 'he', 'hu-HU', 'it-IT', 'ku-IQ', 'nb-NO', 'nl-NL', 'nn-NO', 'pl-PL', 'pt-BR', 'pt-PT', 'ru-RU', 'sl-SI', 'sk-SK', 'sr-RS', 'sr-RS@latin', 'sv-SE', 'tr-TR', 'uk-UA', 'vi-VN']`) and defaults to `en-US`. Locale list is `validator.isAlphanumericLocales`.
 **isAscii(str)**                        | check if the string contains ASCII chars only.
 **isBase32(str)**                       | check if a string is base32 encoded.
+**isBase58(str)**                       | check if a string is base58 encoded.
 **isBase64(str [, options])**          | check if a string is base64 encoded. options is optional and defaults to `{urlSafe: false}`<br/> when `urlSafe` is true it tests the given base64 encoded string is [url safe](https://base64.guru/standards/base64url)
 **isBefore(str [, date])**              | check if the string is a date that's before the specified date.
 **isBIC(str)**                          | check if a string is a BIC (Bank Identification Code) or SWIFT code.

src/index.js

@@ -92,6 +92,7 @@ import isISO31661Alpha2 from './lib/isISO31661Alpha2';
 import isISO31661Alpha3 from './lib/isISO31661Alpha3';
 
 import isBase32 from './lib/isBase32';
+import isBase58 from './lib/isBase58';
 import isBase64 from './lib/isBase64';
 import isDataURI from './lib/isDataURI';
 import isMagnetURI from './lib/isMagnetURI';
@@ -194,6 +195,7 @@ const validator = {
   isISO31661Alpha2,
   isISO31661Alpha3,
   isBase32,
+  isBase58,
   isBase64,
   isDataURI,
   isMagnetURI,

src/lib/isBase58.js

@@ -0,0 +1,12 @@
+import assertString from './util/assertString';
+
+// Accepted chars - 123456789ABCDEFGH JKLMN PQRSTUVWXYZabcdefghijk mnopqrstuvwxyz
+const base58Reg = /^[A-HJ-NP-Za-km-z1-9]*$/;
+
+export default function isBase58(str) {
+  assertString(str);
+  if (base58Reg.test(str)) {
+    return true;
+  }
+  return false;
+}

test/validators.js

@@ -4774,6 +4774,31 @@ describe('Validators', () => {
     });
   });
 
+  it('should validate base58 strings', () => {
+    test({
+      validator: 'isBase58',
+      valid: [
+        'BukQL',
+        '3KMUV89zab',
+        '91GHkLMNtyo98',
+        'YyjKm3H',
+        'Mkhss145TRFg',
+        '7678765677',
+        'abcodpq',
+        'AAVHJKLPY',
+      ],
+      invalid: [
+        '0OPLJH',
+        'IMKLP23',
+        'KLMOmk986',
+        'LL1l1985hG',
+        '*MP9K',
+        'Zm=8JBSWY3DP',
+        ')()(=9292929MKL',
+      ],
+    });
+  });
+
   it('should validate base64 strings', () => {
     test({
       validator: 'isBase64',