Taxonomy: Add 's' as an alias of 'search' in WP_Term_Query

src/wp-includes/class-wp-term-query.php

@@ -158,6 +158,7 @@ class WP_Term_Query {
 	 *                                                   (even if `$hide_empty` is set to true). Default true.
 	 *     @type string          $search                 Search criteria to match terms. Will be SQL-formatted with
 	 *                                                   wildcards before and after. Default empty.
+	 *     @type string          $s                      Alias of `$search`. Default empty.
 	 *     @type string          $name__like             Retrieve terms with criteria by which a term is LIKE
 	 *                                                   `$name__like`. Default empty.
 	 *     @type string          $description__like      Retrieve terms where the description is LIKE
@@ -211,6 +212,7 @@ public function __construct( $query = '' ) {
 			'term_taxonomy_id'       => '',
 			'hierarchical'           => true,
 			'search'                 => '',
+			's'                      => '',
 			'name__like'             => '',
 			'description__like'      => '',
 			'pad_counts'             => false,
@@ -261,6 +263,11 @@ public function parse_query( $query = '' ) {
 
 		$query = wp_parse_args( $query, $this->query_var_defaults );
 
+		// 's' is a shorthand alias for 'search', matching WP_Query convention.
+		if ( '' === $query['search'] && '' !== $query['s'] ) {
+			$query['search'] = $query['s'];
+		}
+
 		$query['number'] = absint( $query['number'] );
 		$query['offset'] = absint( $query['offset'] );
 

tests/phpunit/tests/term/query.php

@@ -1207,4 +1207,76 @@ public function test_query_does_not_have_leading_whitespace() {
 
 		$this->assertSame( ltrim( $q->request ), $q->request, 'The query has leading whitespace' );
 	}
+
+	/**
+	 * @ticket 51811
+	 * @covers WP_Term_Query::parse_query
+	 */
+	public function test_s_param_is_alias_for_search() {
+		register_taxonomy( 'wptests_tax', 'post' );
+
+		$term = self::factory()->term->create(
+			array(
+				'taxonomy' => 'wptests_tax',
+				'name'     => 'Unique Findable Term',
+			)
+		);
+
+		$q = new WP_Term_Query(
+			array(
+				'taxonomy'   => 'wptests_tax',
+				's'          => 'Unique Findable',
+				'hide_empty' => false,
+				'fields'     => 'ids',
+			)
+		);
+
+		$this->assertContains( $term, $q->terms, 'The s parameter should work as an alias for search.' );
+	}
+
+	/**
+	 * @ticket 51811
+	 * @covers WP_Term_Query::parse_query
+	 */
+	public function test_search_takes_precedence_over_s() {
+		register_taxonomy( 'wptests_tax', 'post' );
+
+		$term = self::factory()->term->create(
+			array(
+				'taxonomy' => 'wptests_tax',
+				'name'     => 'Precedence Test Term',
+			)
+		);
+
+		$q = new WP_Term_Query(
+			array(
+				'taxonomy'   => 'wptests_tax',
+				'search'     => 'Precedence Test',
+				's'          => 'nonexistent',
+				'hide_empty' => false,
+				'fields'     => 'ids',
+			)
+		);
+
+		$this->assertContains( $term, $q->terms, 'The search parameter should take precedence over s.' );
+	}
+
+	/**
+	 * @ticket 51811
+	 * @covers WP_Term_Query::parse_query
+	 */
+	public function test_s_param_returns_empty_when_no_match() {
+		register_taxonomy( 'wptests_tax', 'post' );
+
+		$q = new WP_Term_Query(
+			array(
+				'taxonomy'   => 'wptests_tax',
+				's'          => 'absolutelynonexistentterm',
+				'hide_empty' => false,
+				'fields'     => 'ids',
+			)
+		);
+
+		$this->assertEmpty( $q->terms, 'The s parameter should return empty for non-matching terms.' );
+	}
 }