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Changeset 65317

Timestamp:
11/06/2026 07:34:18 PM (3 days ago)
Author:
SergeyBiryukov
Message:

Code Modernization: Simplify isset() guards that initialize empty arrays.

Covering one recognizable idiom: initializing a container to an empty array before writing into it.

-if ( ! isset( $widget_options[ $widget_id ] ) ) {
-       $widget_options[ $widget_id ] = array();
-}
+$widget_options[ $widget_id ] ??= array();

Every one of the 54 changed guards is an isset() check whose entire body is a single = array(); assignment to the tested expression. Each one is handled by one of four rules, so no case needs individual judgement:

  1. Convert the guard to ??= (35 places).
  2. Collapse nested guard chains to the deepest key, since ??= autovivifies missing parent arrays (add_meta_box(), remove_meta_box()): 
    $wp_meta_boxes[ $page ][ $context ] ??= array();
  3. Remove the guard where the next statement writes into the same array or property anyway, since that write creates it (9 places): 
    -if ( ! isset( $object_terms[ $id ] ) ) {
-       $object_terms[ $id ] = array();
-}
 $object_terms[ $id ][ $taxonomy ] = array();
  4. Inline the default where the next statement reassigns the same expression from an array_merge() call (3 places): 
    $this->headers[ $key ] = array_merge( $this->headers[ $key ] ?? array(), $value );

Why this is safe

  • ??= requires PHP 7.4, which is already the minimum supported version.
  • ??=, ?? and ! isset() test the same condition, so the default is used in exactly the same cases.
  • Only blocks whose body is a single assignment were changed. Any guard containing further statements was skipped, since ??= would let those statements run unconditionally.
  • Removed guards are only those directly followed by a write into the same array, or into a property of a stdClass object, where PHP creates the missing container the same way.
  • No behavior change.

Developed in ​https://github.com/WordPress/wordpress-develop/pull/12912.

Props Soean, mukesh27, westonruter.
See #65823.

Location:
trunk/src
Files:
32 edited

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