[wp-trac] [WordPress Trac] #61647: Catch ArgumentCountError in apply_filters, and prompt developers to check accepted_args

[WordPress Trac]

#61647: Catch ArgumentCountError in apply_filters, and prompt developers to check
accepted_args
-------------------------+-----------------------------
 Reporter:  gqqnbig      |      Owner:  (none)
     Type:  enhancement  |     Status:  new
 Priority:  normal       |  Milestone:  Awaiting Review
Component:  General      |    Version:  trunk
 Severity:  normal       |   Keywords:
  Focuses:               |
-------------------------+-----------------------------
 {{{
 diff --git a/src/wp-includes/class-wp-hook.php b/src/wp-includes/class-wp-
 hook.php
 index d95691d..f91f986 100644
 --- a/src/wp-includes/class-wp-hook.php
 +++ b/src/wp-includes/class-wp-hook.php
 @@ -317,13 +317,17 @@ final class WP_Hook implements Iterator, ArrayAccess
 {
                                         $args[0] = $value;
                                 }

 -                               // Avoid the array_slice() if possible.
 -                               if ( 0 === $the_['accepted_args'] ) {
 -                                       $value = call_user_func(
 $the_['function'] );
 -                               } elseif ( $the_['accepted_args'] >=
 $num_args ) {
 -                                       $value = call_user_func_array(
 $the_['function'], $args );
 -                               } else {
 -                                       $value = call_user_func_array(
 $the_['function'], array_slice( $args, 0, $the_['accepted_args'] ) );
 +                               try {
 +                                       // Avoid the array_slice() if
 possible.
 +                                       if (0 === $the_['accepted_args'])
 {
 +                                               $value =
 call_user_func($the_['function']);
 +                                       } elseif ($the_['accepted_args']
 >= $num_args) {
 +                                               $value =
 call_user_func_array($the_['function'], $args);
 +                                       } else {
 +                                               $value =
 call_user_func_array($the_['function'], array_slice($args, 0,
 $the_['accepted_args']));
 +                                       }
 +                               } catch (ArgumentCountError $e) {
 +                                       throw new
 ArgumentCountError($e->getMessage() . ". Did you set a correct
 accepted_args in add_action() or add_filter()?");
                                 }
                         }
                 } while ( false !== next( $this->iterations[
 $nesting_level ] ) );

 }}}

 I would like to propose this change. Add try-catch block around
 call_user_func_array in apply_filters(), so that (beginner) developers are
 hinted that they might forget to change accepted_args.

 As a beginner WordPress developer, I encounter ArgumentCountError when I
 write the following code. I wasn't aware of the optional argument
 $accepted_args. My pull request thus gives a hint.




 {{{#!php
 <?php
 add_action('update_option', 'option_changed');


 function option_changed($option_name, $old_value, $new_value) {
         ...
 }
 }}}

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/61647>
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