Editor: Opt to dequeue assets enqueued in hidden blocks, rather than to enqueue assets for non-hidden blocks.

This eliminates constant emptying out of the queues for styles, scripts, and script modules before rendering each block. This ensures that `wp_script_is()`/`wp_style_is()` will return true for assets that are actually enqueued. The `WP_Script_Modules::$queue` member which was made public in [60930] is now made private in favor of a `WP_Script_Modules::get_queue()` method, since there is no need to clear out the queue before rendering each block and restore after the rendering is complete. 

Finally, as a very special case for unusual blocks which contain `wp_head()`, a check is done to see if the `wp_enqueue_scripts` action occurred during the rendering of a block; if so, then no assets will be dequeued even if no markup is rendered in the block, since it may be that a script was enqueued for the footer and not the head. 

Developed in #10252

Follow-up to [60930].

Props westonruter, dd32, peterwilsoncc, nikunj8866, krupajnanda.
Fixes #63676.


git-svn-id: https://develop.svn.wordpress.org/trunk@60951 602fd350-edb4-49c9-b593-d223f7449a82

Author: westonruter

src/wp-includes/class-wp-block.php

@@ -492,13 +492,12 @@ public function replace_rich_text( $rich_text ) {
 	public function render( $options = array() ) {
 		global $post;
 
-		// Capture the current assets queues and then clear out to capture the diff of what was introduced by rendering.
+		$before_wp_enqueue_scripts_count = did_action( 'wp_enqueue_scripts' );
+
+		// Capture the current assets queues.
 		$before_styles_queue         = wp_styles()->queue;
 		$before_scripts_queue        = wp_scripts()->queue;
-		$before_script_modules_queue = wp_script_modules()->queue;
-		wp_styles()->queue           = array();
-		wp_scripts()->queue          = array();
-		wp_script_modules()->queue   = array();
+		$before_script_modules_queue = wp_script_modules()->get_queue();
 
 		/*
 		 * There can be only one root interactive block at a time because the rendered HTML of that block contains
@@ -670,21 +669,27 @@ public function render( $options = array() ) {
 		}
 
 		// Capture the new assets enqueued during rendering, and restore the queues the state prior to rendering.
-		$new_styles_queue          = wp_styles()->queue;
-		$new_scripts_queue         = wp_scripts()->queue;
-		$new_script_modules_queue  = wp_script_modules()->queue;
-		wp_styles()->queue         = $before_styles_queue;
-		wp_scripts()->queue        = $before_scripts_queue;
-		wp_script_modules()->queue = $before_script_modules_queue;
-		$has_new_styles            = count( $new_styles_queue ) > 0;
-		$has_new_scripts           = count( $new_scripts_queue ) > 0;
-		$has_new_script_modules    = count( $new_script_modules_queue ) > 0;
-
-		// Merge the newly enqueued assets with the existing assets if the rendered block is not empty.
+		$after_styles_queue         = wp_styles()->queue;
+		$after_scripts_queue        = wp_scripts()->queue;
+		$after_script_modules_queue = wp_script_modules()->get_queue();
+
+		/*
+		 * As a very special case, a dynamic block may in fact include a call to wp_head() (and thus wp_enqueue_scripts()),
+		 * in which all of its enqueued assets are targeting wp_footer. In this case, nothing would be printed, but this
+		 * shouldn't indicate that the just-enqueued assets should be dequeued due to it being an empty block.
+		 */
+		$just_did_wp_enqueue_scripts = ( did_action( 'wp_enqueue_scripts' ) !== $before_wp_enqueue_scripts_count );
+
+		$has_new_styles         = ( $before_styles_queue !== $after_styles_queue );
+		$has_new_scripts        = ( $before_scripts_queue !== $after_scripts_queue );
+		$has_new_script_modules = ( $before_script_modules_queue !== $after_script_modules_queue );
+
+		// Dequeue the newly enqueued assets with the existing assets if the rendered block was empty & wp_enqueue_scripts did not fire.
 		if (
+			! $just_did_wp_enqueue_scripts &&
 			( $has_new_styles || $has_new_scripts || $has_new_script_modules ) &&
 			(
-				trim( $block_content ) !== '' ||
+				trim( $block_content ) === '' &&
 				/**
 				 * Filters whether to enqueue assets for a block which has no rendered content.
 				 *
@@ -693,17 +698,17 @@ public function render( $options = array() ) {
 				 * @param bool   $enqueue    Whether to enqueue assets.
 				 * @param string $block_name Block name.
 				 */
-				(bool) apply_filters( 'enqueue_empty_block_content_assets', false, $this->name )
+				! (bool) apply_filters( 'enqueue_empty_block_content_assets', false, $this->name )
 			)
 		) {
-			if ( $has_new_styles ) {
-				wp_styles()->queue = array_unique( array_merge( wp_styles()->queue, $new_styles_queue ) );
+			foreach ( array_diff( $after_styles_queue, $before_styles_queue ) as $handle ) {
+				wp_dequeue_style( $handle );
 			}
-			if ( $has_new_scripts ) {
-				wp_scripts()->queue = array_unique( array_merge( wp_scripts()->queue, $new_scripts_queue ) );
+			foreach ( array_diff( $after_scripts_queue, $before_scripts_queue ) as $handle ) {
+				wp_dequeue_script( $handle );
 			}
-			if ( $has_new_script_modules ) {
-				wp_script_modules()->queue = array_unique( array_merge( wp_script_modules()->queue, $new_script_modules_queue ) );
+			foreach ( array_diff( $after_script_modules_queue, $before_script_modules_queue ) as $handle ) {
+				wp_dequeue_script_module( $handle );
 			}
 		}
 

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

@@ -28,7 +28,7 @@ class WP_Script_Modules {
 	 * @since 6.9.0
 	 * @var string[]
 	 */
-	public $queue = array();
+	private $queue = array();
 
 	/**
 	 * Tracks whether the @wordpress/a11y script module is available.
@@ -137,6 +137,17 @@ public function register( string $id, string $src, array $deps = array(), $versi
 		}
 	}
 
+	/**
+	 * Gets IDs for queued script modules.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @return string[] Script module IDs.
+	 */
+	public function get_queue(): array {
+		return $this->queue;
+	}
+
 	/**
 	 * Checks if the provided fetchpriority is valid.
 	 *
@@ -237,7 +248,7 @@ public function enqueue( string $id, string $src = '', array $deps = array(), $v
 	 * @param string $id The identifier of the script module.
 	 */
 	public function dequeue( string $id ) {
-		$this->queue = array_diff( $this->queue, array( $id ) );
+		$this->queue = array_values( array_diff( $this->queue, array( $id ) ) );
 	}
 
 	/**

tests/phpunit/tests/blocks/wpBlock.php

@@ -543,6 +543,62 @@ static function ( $content ) {
 				'expected_scripts'        => array( 'static-view-script', 'static-child-view-script', 'dynamic-view-script' ),
 				'expected_script_modules' => array( 'static-view-script-module', 'static-child-view-script-module', 'dynamic-view-script-module' ),
 			),
+			'admin_bar_assets_enqueued_in_block'      => array(
+				'set_up'                  => static function () {
+					wp_enqueue_script( 'admin-bar' );
+					wp_enqueue_style( 'admin-bar' );
+
+					add_filter(
+						'render_block_core/static',
+						static function ( $content ) {
+							$processor = new WP_HTML_Tag_Processor( $content );
+							$processor->next_tag();
+							$processor->add_class( wp_script_is( 'admin-bar', 'enqueued' ) ? 'yes-admin-bar-script-enqueued' : 'not-admin-bar-script-enqueued' );
+							$processor->add_class( wp_style_is( 'admin-bar', 'enqueued' ) ? 'yes-admin-bar-style-enqueued' : 'not-admin-bar-style-enqueued' );
+							return $processor->get_updated_html();
+						},
+						10,
+						3
+					);
+				},
+				'block_markup'            => '<!-- wp:static --><div class="static"></div><!-- /wp:static -->',
+				'expected_rendered_block' => '
+					<div class="static yes-admin-bar-script-enqueued yes-admin-bar-style-enqueued"></div>
+				',
+				'expected_styles'         => array( 'static-view-style', 'admin-bar' ),
+				'expected_scripts'        => array( 'static-view-script', 'admin-bar' ),
+				'expected_script_modules' => array( 'static-view-script-module' ),
+			),
+			'enqueues_in_wp_head_block'               => array(
+				'set_up'                  => static function () {
+					remove_all_actions( 'wp_head' );
+					remove_all_actions( 'wp_enqueue_scripts' );
+
+					add_action( 'wp_head', 'wp_enqueue_scripts', 1 );
+					add_action( 'wp_head', 'wp_print_styles', 8 );
+					add_action( 'wp_head', 'wp_print_head_scripts', 9 );
+					remove_action( 'wp_print_styles', 'print_emoji_styles' );
+
+					add_action(
+						'wp_enqueue_scripts',
+						static function () {
+							wp_enqueue_script( 'for-footer', '/footer.js', array(), null, array( 'in_footer' => true ) );
+						}
+					);
+					add_action(
+						'wp_head',
+						static function () {
+							wp_enqueue_style( 'for-footer', '/footer.css', array(), null );
+						},
+						10000
+					);
+				},
+				'block_markup'            => '<!-- wp:wp-head /-->',
+				'expected_rendered_block' => '',
+				'expected_styles'         => array( 'for-footer' ),
+				'expected_scripts'        => array( 'for-footer' ),
+				'expected_script_modules' => array(),
+			),
 		);
 	}
 
@@ -562,6 +618,16 @@ public function test_render_enqueues_scripts_and_styles( ?Closure $set_up, strin
 		if ( $set_up instanceof Closure ) {
 			$set_up();
 		}
+
+		$this->registry->register(
+			'core/wp-head',
+			array(
+				'render_callback' => static function () {
+					return get_echo( 'wp_head' );
+				},
+			)
+		);
+
 		wp_register_style( 'static-view-style', home_url( '/static-view-style.css' ) );
 		wp_register_script( 'static-view-script', home_url( '/static-view-script.js' ) );
 		wp_register_script_module( 'static-view-script-module', home_url( '/static-view-script-module.js' ) );
@@ -608,44 +674,16 @@ public function test_render_enqueues_scripts_and_styles( ?Closure $set_up, strin
 		$block          = new WP_Block( $parsed_block, $context, $this->registry );
 		$rendered_block = $block->render();
 
+		$this->assertSameSets( $expected_styles, wp_styles()->queue, 'Enqueued styles do not meet expectations' );
+		$this->assertSameSets( $expected_scripts, wp_scripts()->queue, 'Enqueued scripts do not meet expectations' );
+		$this->assertSameSets( $expected_script_modules, wp_script_modules()->get_queue(), 'Enqueued script modules do not meet expectations' );
+
 		$this->assertEqualHTML(
 			$expected_rendered_block,
 			$rendered_block,
 			'<body>',
 			"Rendered block does not contain expected HTML:\n$rendered_block"
 		);
-
-		remove_action( 'wp_print_styles', 'print_emoji_styles' );
-
-		$actual_styles  = array();
-		$printed_styles = get_echo( 'wp_print_styles' );
-		$processor      = new WP_HTML_Tag_Processor( $printed_styles );
-		while ( $processor->next_tag( array( 'tag_name' => 'LINK' ) ) ) {
-			if ( 1 === preg_match( '/^(.+)-css$/', $processor->get_attribute( 'id' ), $matches ) ) {
-				$actual_styles[] = $matches[1];
-			}
-		}
-		$this->assertSameSets( $expected_styles, $actual_styles, 'Enqueued styles do not meet expectations' );
-
-		$actual_scripts  = array();
-		$printed_scripts = get_echo( 'wp_print_scripts' );
-		$processor       = new WP_HTML_Tag_Processor( $printed_scripts );
-		while ( $processor->next_tag( array( 'tag_name' => 'SCRIPT' ) ) ) {
-			if ( 1 === preg_match( '/^(.+)-js$/', $processor->get_attribute( 'id' ), $matches ) ) {
-				$actual_scripts[] = $matches[1];
-			}
-		}
-		$this->assertSameSets( $expected_scripts, $actual_scripts, 'Enqueued scripts do not meet expectations' );
-
-		$actual_script_modules  = array();
-		$printed_script_modules = get_echo( array( wp_script_modules(), 'print_enqueued_script_modules' ) );
-		$processor              = new WP_HTML_Tag_Processor( $printed_script_modules );
-		while ( $processor->next_tag( array( 'tag_name' => 'SCRIPT' ) ) ) {
-			if ( 1 === preg_match( '/^(.+)-js-module$/', $processor->get_attribute( 'id' ), $matches ) ) {
-				$actual_script_modules[] = $matches[1];
-			}
-		}
-		$this->assertSameSets( $expected_script_modules, $actual_script_modules, 'Enqueued script modules do not meet expectations' );
 	}
 
 	/**

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

@@ -1676,28 +1676,30 @@ private function normalize_markup_for_snapshot( string $markup ): string {
 	}
 
 	/**
-	 * Tests that directly manipulating the queue works as expected.
+	 * Tests that manipulating the queue works as expected.
 	 *
 	 * @ticket 63676
 	 *
+	 * @covers WP_Script_Modules::get_queue
 	 * @covers WP_Script_Modules::queue
 	 * @covers WP_Script_Modules::dequeue
 	 */
 	public function test_direct_queue_manipulation() {
 		$this->script_modules->register( 'foo', '/foo.js' );
 		$this->script_modules->register( 'bar', '/bar.js' );
 		$this->script_modules->register( 'baz', '/baz.js' );
-		$this->assertSame( array(), $this->script_modules->queue, 'Expected queue to be empty.' );
+		$this->assertSame( array(), $this->script_modules->get_queue(), 'Expected queue to be empty.' );
 		$this->script_modules->enqueue( 'foo' );
 		$this->script_modules->enqueue( 'foo' );
 		$this->script_modules->enqueue( 'bar' );
-		$this->assertSame( array( 'foo', 'bar' ), $this->script_modules->queue, 'Expected two deduplicated queued items.' );
-		$this->script_modules->queue = array( 'baz' );
-		$this->script_modules->enqueue( 'bar' );
-		$this->assertSame( array( 'baz', 'bar' ), $this->script_modules->queue, 'Expected queue updated via setter and enqueue method to have two items.' );
+		$this->assertSame( array( 'foo', 'bar' ), $this->script_modules->get_queue(), 'Expected two deduplicated queued items.' );
+		$this->script_modules->dequeue( 'foo' );
+		$this->script_modules->dequeue( 'foo' );
+		$this->script_modules->enqueue( 'baz' );
+		$this->assertSame( array( 'bar', 'baz' ), $this->script_modules->get_queue(), 'Expected items tup be updated after dequeue and enqueue.' );
 		$this->script_modules->dequeue( 'baz' );
 		$this->script_modules->dequeue( 'bar' );
-		$this->assertSame( array(), $this->script_modules->queue, 'Expected queue to be empty after dequeueing both items.' );
+		$this->assertSame( array(), $this->script_modules->get_queue(), 'Expected queue to be empty after dequeueing both items.' );
 	}
 
 	/**