composer require "penance316/laravel-base64-validator"
Add the required validator to boot method of app/Providers/AppServiceProvider.php
Validator::extend('base64', 'Penance316\Validators\Base64Validator@validateBase64');
Add the following lines to resources/lang/en/validation.php
'base64' => 'The :attribute must be a valid Base64 string.',
Use like other validators
...
'reference' => 'required|max:255',
'data' => 'required|base64',
'email' => 'required|email',
...
Use vendor phpunit
./vendor/phpunit/phpunit/phpunit --testdox