Why when I instantiate wp_error in a validation method my user registration method stops working?

Question

I would really, really, appreciate any insight I can get here.

I'm working on a WordPress plugin that registers users in WordPress and want to validate data submitted through the form. I have a class for this, here's a condensed version of it:

namespace PluginName\Includes\Forms\Classes;

class Validation {

    public function validate_fields($field, $form_type){

      $errors = new WP_Error();
      $validated_fields = [];

      if(!is_email($field)):
        $errors->add('not_email', __('Entered an invalid email', 'plugin-name'));
      else:
        $validated_fields['user_email'] = $field;
      endif;

      //other validations

      $error_code = $errors->get_error_code();
      if(!empty($error_code)):
         return $errors;
      endif;

      return $validated_fields;

    }
}

In my user registration class I instantiate the class above to get whatever it returns either and array of field data or errors.

Here's my Register_User class condensed:

namespace PluginName\Includes\Forms\Classes;

class Register_User{

    public function __construct(){
        add_action('wp_ajax_pn_register_user', [$this, 'pn_register_user']);
        add_action('wp_ajax_nopriv_pn_register_user', [$this, 'pn_register_user']);
    }

    public function pn_register_user(){
    
        if (!check_ajax_referer( 'reg_nonce' )):
            wp_die();
        endif;

        $form_validation = new Validation();
        $form_validation_results = $form_validation->validate_fields($_POST, 'registration');

        if(is_wp_error($form_validation_results)):
            
            error_log('Some error happened');

        else:

            error_log('No Errors to report');

            $userdata = array(
                'user_email' => $form_validation_results['user_email']
                //other fields
            );

            wp_insert_user($userdata);

        endif;

        wp_die();

    }

}

This does not work if I have this line in the validation class: $errors = new WP_Error(); - the form is submitted but no user is registered as soon as I comment out everything related to WP_Error the user is registered normally. And it's not due to any validation, even with no validation and just the WP_Error object instantiated it does not work.

Again, I would really appreciate any help that I can get, my head is about to explode. I couldn't find anything on the site or elsewhere. I'm not sure if it's a scoping issue or an ajax issue? regarding the former, I tried making $errors global but still no results.

Please help

Answer 1

It seems you need to use $errors = new \WP_Error(); in your code, since WP_Error isn't part of your namespace.

I ran a quick test on my machine, using wp-cli commands:

Using new WP_Error():

% wp eval 'namespace PJ\NS\Test; $x = new WP_Error(); var_dump( $x );'
Fatal error: Uncaught Error: Class 'PJ\NS\Test\WP_Error' not found in phar:///usr/local/bin/wp/vendor/wp-cli/eval-command/src/Eval_Command.php(37) : eval()'d code:1
Stack trace:
#0 phar:///usr/local/bin/wp/vendor/wp-cli/eval-command/src/Eval_Command.php(37): eval()
#1 [internal function]: Eval_Command->__invoke(Array, Array)
#2 phar:///usr/local/bin/wp/vendor/wp-cli/wp-cli/php/WP_CLI/Dispatcher/CommandFactory.php(98): call_user_func(Array, Array, Array)
#3 [internal function]: WP_CLI\Dispatcher\CommandFactory::WP_CLI\Dispatcher\{closure}(Array, Array)
#4 phar:///usr/local/bin/wp/vendor/wp-cli/wp-cli/php/WP_CLI/Dispatcher/Subcommand.php(451): call_user_func(Object(Closure), Array, Array)
#5 phar:///usr/local/bin/wp/vendor/wp-cli/wp-cli/php/WP_CLI/Runner.php(371): WP_CLI\Dispatcher\Subcommand->invoke(Array, Array, Array)
#6 phar:///usr/local/bin/wp/vendor/wp-cli/wp-cli/php/WP_CLI/Runner.php(394): WP_CLI\Runner->run_command(Array, Array)
#7 phar:///usr/local/bin/wp/vendor/wp-cli/wp-cli/php/WP_CLI/Runner.php(87): WP_CLI\Runne in phar:///usr/local/bin/wp/vendor/wp-cli/eval-command/src/Eval_Command.php(37) : eval()'d code on line 1
Error: There has been a critical error on your website.Learn more about debugging in WordPress. There has been a critical error on your website.

Using new \WP_Error():

% wp eval 'namespace PJ\NS\Test; $x = new \WP_Error(); var_dump( $x );'
object(WP_Error)#1516 (2) {
  ["errors"]=>
  array(0) {
  }
  ["error_data"]=>
  array(0) {
  }
}