Only consider enqueued dependents when calculating highest fetchpriority

Author: westonruter

src/wp-includes/class-wp-script-modules.php

@@ -461,9 +461,9 @@ private function print_script_module( string $id ) {
 			'id'   => $id . '-js-module',
 		);
 
-		$script_module = $this->registered[ $id ];
-		$dependents    = $this->get_recursive_dependents( $id );
-		$fetchpriority = $this->get_highest_fetchpriority( array_merge( array( $id ), $dependents ) );
+		$script_module     = $this->registered[ $id ];
+		$queued_dependents = array_intersect( $this->queue, $this->get_recursive_dependents( $id ) );
+		$fetchpriority     = $this->get_highest_fetchpriority( array_merge( array( $id ), $queued_dependents ) );
 		if ( 'auto' !== $fetchpriority ) {
 			$attributes['fetchpriority'] = $fetchpriority;
 		}

tests/phpunit/tests/script-modules/wpScriptModules.php

@@ -1553,24 +1553,46 @@ public function test_set_fetchpriority_with_invalid_value() {
 	 */
 	public function data_provider_to_test_fetchpriority_bumping(): array {
 		return array(
-			'enqueue_bajo' => array(
+			'enqueue_bajo'          => array(
 				'enqueues' => array( 'bajo' ),
+				'expected' => array(
+					'preload_links' => array(),
+					'script_tags'   => array(
+						'bajo' => array(
+							'url'           => '/bajo.js',
+							'fetchpriority' => 'low', // Priority of 'low' not 'high' because the 'auto' dependent was not enqueued.
+							'in_footer'     => false,
+						),
+					),
+					'import_map'    => array(
+						'dyno' => '/dyno.js',
+					),
+				),
+			),
+			'enqueue_bajo_and_auto' => array(
+				'enqueues' => array( 'bajo', 'auto' ),
 				'expected' => array(
 					'preload_links' => array(),
 					'script_tags'   => array(
 						'bajo' => array(
 							'url'                   => '/bajo.js',
-							'fetchpriority'         => 'high',
+							'fetchpriority'         => 'auto',
 							'in_footer'             => false,
 							'data-wp-fetchpriority' => 'low',
 						),
+						'auto' => array(
+							'url'           => '/auto.js',
+							'fetchpriority' => 'auto',
+							'in_footer'     => false,
+						),
 					),
 					'import_map'    => array(
 						'dyno' => '/dyno.js',
+						'bajo' => '/bajo.js',
 					),
 				),
 			),
-			'enqueue_auto' => array(
+			'enqueue_auto'          => array(
 				'enqueues' => array( 'auto' ),
 				'expected' => array(
 					'preload_links' => array(
@@ -1582,10 +1604,9 @@ public function data_provider_to_test_fetchpriority_bumping(): array {
 					),
 					'script_tags'   => array(
 						'auto' => array(
-							'url'                   => '/auto.js',
-							'fetchpriority'         => 'high',
-							'in_footer'             => false,
-							'data-wp-fetchpriority' => 'auto',
+							'url'           => '/auto.js',
+							'fetchpriority' => 'auto', // Priority of 'auto' not 'high' because the 'alto' dependent was not enqueued.
+							'in_footer'     => false,
 						),
 					),
 					'import_map'    => array(
@@ -1594,7 +1615,7 @@ public function data_provider_to_test_fetchpriority_bumping(): array {
 					),
 				),
 			),
-			'enqueue_alto' => array(
+			'enqueue_alto'          => array(
 				'enqueues' => array( 'alto' ),
 				'expected' => array(
 					'preload_links' => array(
@@ -1833,6 +1854,10 @@ public function test_default_script_modules() {
 	 * Tests expected priority is used when a dependent is registered but not enqueued.
 	 *
 	 * @ticket 64429
+	 *
+	 * @covers ::wp_default_script_modules
+	 * @covers WP_Script_Modules::print_enqueued_script_modules
+	 * @covers WP_Script_Modules::get_highest_fetchpriority
 	 */
 	public function test_priority_of_dependency_for_non_enqueued_dependent() {
 		wp_default_script_modules();