From 39a11a85f520a8b36e433f97fb35e039ce7937f4 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Tue, 8 Oct 2024 16:10:13 +0200
Subject: [PATCH 01/42] Add "expose" logic to script modules

This allows for script modules to be exposed in the import map
regardless of being a dependency or enqueued.

This will enable scripts to depend on script modules by requesting they
be exposed.
---
 src/wp-includes/class-wp-script-modules.php | 33 ++++++++++++++++++---
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index dbfa038f8cbe2..4f9973236fecb 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -30,6 +30,18 @@ class WP_Script_Modules {
 	 */
 	private $enqueued_before_registered = array();
 
+	/**
+	 * Holds script module identifiers that have been requested for exposure.
+	 *
+	 * "Exposed" indicates that the script module should be exposed in the
+	 * import map regardless of whether it is a dependency of another script
+	 * module.
+	 *
+	 * @since 6.8.0
+	 * @var array<string, true>
+	 */
+	private $exposed = array();
+
 	/**
 	 * Tracks whether the @wordpress/a11y script module is available.
 	 *
@@ -148,6 +160,17 @@ public function enqueue( string $id, string $src = '', array $deps = array(), $v
 		}
 	}
 
+	/**
+	 * Marks the script module so it will be exposed in the import map.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @param string $id The identifier of the script module.
+	 */
+	public function expose( string $id ) {
+		$this->exposed[ $id ] = true;
+	}
+
 	/**
 	 * Unmarks the script module so it will no longer be enqueued in the page.
 	 *
@@ -262,12 +285,14 @@ public function print_import_map() {
 	 *
 	 * @since 6.5.0
 	 *
-	 * @return array Array with an `imports` key mapping to an array of script module identifiers and their respective
-	 *               URLs, including the version query.
+	 * @return array Array with an `imports` key mapping to an array of script
+	 *               module identifiers and their respective URLs, including
+	 *               the version query.
 	 */
 	private function get_import_map(): array {
-		$imports = array();
-		foreach ( $this->get_dependencies( array_keys( $this->get_marked_for_enqueue() ) ) as $id => $script_module ) {
+		$imports           = array();
+		$script_module_ids = array_unique( array_keys( $this->exposed ) + array_keys( $this->get_marked_for_enqueue() ) );
+		foreach ( $this->get_dependencies( $script_module_ids ) as $id => $script_module ) {
 			$imports[ $id ] = $this->get_src( $id );
 		}
 		return array( 'imports' => $imports );

From 65fd1dfc7e34bda55a18ea912420367c1cfe2b74 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Tue, 8 Oct 2024 16:14:57 +0200
Subject: [PATCH 02/42] Make get_src return nullable

---
 src/wp-includes/class-wp-script-modules.php | 26 ++++++++++++++++-----
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 4f9973236fecb..801ab09ef06d8 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -231,10 +231,15 @@ public function add_hooks() {
 	 */
 	public function print_enqueued_script_modules() {
 		foreach ( $this->get_marked_for_enqueue() as $id => $script_module ) {
+			$src = $this->get_src( $id );
+			if ( null === $src ) {
+				continue;
+			}
+
 			wp_print_script_tag(
 				array(
 					'type' => 'module',
-					'src'  => $this->get_src( $id ),
+					'src'  => $src,
 					'id'   => $id . '-js-module',
 				)
 			);
@@ -251,11 +256,16 @@ public function print_enqueued_script_modules() {
 	 */
 	public function print_script_module_preloads() {
 		foreach ( $this->get_dependencies( array_keys( $this->get_marked_for_enqueue() ), array( 'static' ) ) as $id => $script_module ) {
+			$src = $this->get_src( $id );
+			if ( null === $src ) {
+				continue;
+			}
+
 			// Don't preload if it's marked for enqueue.
 			if ( true !== $script_module['enqueue'] ) {
 				echo sprintf(
 					'<link rel="modulepreload" href="%s" id="%s">',
-					esc_url( $this->get_src( $id ) ),
+					esc_url( $src ),
 					esc_attr( $id . '-js-modulepreload' )
 				);
 			}
@@ -293,7 +303,11 @@ private function get_import_map(): array {
 		$imports           = array();
 		$script_module_ids = array_unique( array_keys( $this->exposed ) + array_keys( $this->get_marked_for_enqueue() ) );
 		foreach ( $this->get_dependencies( $script_module_ids ) as $id => $script_module ) {
-			$imports[ $id ] = $this->get_src( $id );
+			$src = $this->get_src( $id );
+			if ( null === $src ) {
+				continue;
+			}
+			$imports[ $id ] = $src;
 		}
 		return array( 'imports' => $imports );
 	}
@@ -360,11 +374,11 @@ function ( $dependency_script_modules, $id ) use ( $import_types ) {
 	 * @since 6.5.0
 	 *
 	 * @param string $id The script module identifier.
-	 * @return string The script module src with a version if relevant.
+	 * @return string|null The script module src with a version if relevant.
 	 */
-	private function get_src( string $id ): string {
+	private function get_src( string $id ): ?string {
 		if ( ! isset( $this->registered[ $id ] ) ) {
-			return '';
+			return null;
 		}
 
 		$script_module = $this->registered[ $id ];

From 843e1e0a077cc7f7c02ed9af00d3d6a72319575b Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Mon, 16 Dec 2024 17:14:55 +0100
Subject: [PATCH 03/42] Rework, rename, add tests

---
 src/wp-includes/class-wp-script-modules.php   | 37 ++++++++++++++-----
 .../tests/script-modules/wpScriptModules.php  | 32 ++++++++++++++--
 2 files changed, 55 insertions(+), 14 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 801ab09ef06d8..b1544813bff27 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -31,16 +31,20 @@ class WP_Script_Modules {
 	private $enqueued_before_registered = array();
 
 	/**
-	 * Holds script module identifiers that have been requested for exposure.
+	 * Holds script module identifiers that have been marked for inclusion in the import map.
 	 *
-	 * "Exposed" indicates that the script module should be exposed in the
-	 * import map regardless of whether it is a dependency of another script
-	 * module.
+	 * A script module that appears here should be include in the import map regardless of
+	 * whether it is a dependency of another script module.
+	 *
+	 * The values in this array are always `null`. The presence of a Module IDs
+	 * as an array key marks the script module for inclusion in the import map.
+	 * Different values are reserved for possible future use.
 	 *
 	 * @since 6.8.0
-	 * @var array<string, true>
+	 *
+	 * @var array<string, null>
 	 */
-	private $exposed = array();
+	private $marked_for_inclusion = array();
 
 	/**
 	 * Tracks whether the @wordpress/a11y script module is available.
@@ -161,14 +165,18 @@ public function enqueue( string $id, string $src = '', array $deps = array(), $v
 	}
 
 	/**
-	 * Marks the script module so it will be exposed in the import map.
+	 * Marks the script module for inclusion in the import map.
+	 *
+	 * Script Modules can rely on the script module dependency graph to include script modules
+	 * in the import map. This method makes it possible to mark a script module for inclusion
+	 * in the import map without relying on the script module dependency graph.
 	 *
 	 * @since 6.8.0
 	 *
 	 * @param string $id The identifier of the script module.
 	 */
-	public function expose( string $id ) {
-		$this->exposed[ $id ] = true;
+	public function include_in_import_map( string $id ) {
+		$this->marked_for_inclusion[ $id ] = null;
 	}
 
 	/**
@@ -301,7 +309,8 @@ public function print_import_map() {
 	 */
 	private function get_import_map(): array {
 		$imports           = array();
-		$script_module_ids = array_unique( array_keys( $this->exposed ) + array_keys( $this->get_marked_for_enqueue() ) );
+		$script_module_ids = array_unique( array_keys( $this->marked_for_inclusion ) + array_keys( $this->get_marked_for_enqueue() ) );
+
 		foreach ( $this->get_dependencies( $script_module_ids ) as $id => $script_module ) {
 			$src = $this->get_src( $id );
 			if ( null === $src ) {
@@ -309,6 +318,14 @@ private function get_import_map(): array {
 			}
 			$imports[ $id ] = $src;
 		}
+		foreach ( $this->marked_for_inclusion as $id => $_ ) {
+			$src = $this->get_src( $id );
+			if ( null === $src ) {
+				continue;
+			}
+			$imports[ $id ] = $src;
+		}
+
 		return array( 'imports' => $imports );
 	}
 
diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index 85f9599f0dac3..ce757018631f9 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -34,7 +34,7 @@ public function set_up() {
 	 *
 	 * @return array Enqueued script module URLs, keyed by script module identifier.
 	 */
-	public function get_enqueued_script_modules() {
+	private function get_enqueued_script_modules() {
 		$script_modules_markup   = get_echo( array( $this->script_modules, 'print_enqueued_script_modules' ) );
 		$p                       = new WP_HTML_Tag_Processor( $script_modules_markup );
 		$enqueued_script_modules = array();
@@ -54,10 +54,12 @@ public function get_enqueued_script_modules() {
 	 *
 	 * @return array Import map entry URLs, keyed by script module identifier.
 	 */
-	public function get_import_map() {
+	private function get_import_map() {
 		$import_map_markup = get_echo( array( $this->script_modules, 'print_import_map' ) );
 		preg_match( '/<script type="importmap" id="wp-importmap">.*?(\{.*\}).*?<\/script>/s', $import_map_markup, $import_map_string );
-		return json_decode( $import_map_string[1], true )['imports'];
+		return isset( $import_map_string[1] )
+			? json_decode( $import_map_string[1], true )['imports']
+			: array();
 	}
 
 	/**
@@ -65,7 +67,7 @@ public function get_import_map() {
 	 *
 	 * @return array Preloaded script module URLs, keyed by script module identifier.
 	 */
-	public function get_preloaded_script_modules() {
+	private function get_preloaded_script_modules() {
 		$preloaded_markup         = get_echo( array( $this->script_modules, 'print_script_module_preloads' ) );
 		$p                        = new WP_HTML_Tag_Processor( $preloaded_markup );
 		$preloaded_script_modules = array();
@@ -906,4 +908,26 @@ public static function data_invalid_script_module_data(): array {
 			'string'   => array( 'string' ),
 		);
 	}
+
+	/**
+	 * @ticket 61500
+	 */
+	public function test_added_module_appears_in_importmap() {
+		$this->script_modules->register( 'dependency', '/dep.js' );
+		$this->script_modules->register( 'example', '/example.js', array( 'dependency' ) );
+
+		// Nothing printed now.
+		$this->assertSame( array(), $this->get_enqueued_script_modules() );
+		$this->assertSame( array(), $this->get_preloaded_script_modules() );
+		$this->assertSame( array(), $this->get_import_map() );
+
+		// After including, the importmap should be populated.
+		$this->script_modules->include_in_import_map( 'example' );
+		$this->assertSame( array(), $this->get_enqueued_script_modules() );
+		$this->assertSame( array(), $this->get_preloaded_script_modules() );
+
+		$import_map = $this->get_import_map();
+		$this->assertArrayHasKey( 'example', $import_map );
+		$this->assertArrayHasKey( 'dependency', $import_map );
+	}
 }

From 2e180cf61f260842ad881c196fbbe9d84852e01b Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Tue, 17 Dec 2024 09:55:45 +0100
Subject: [PATCH 04/42] Remove uniqueness checks

---
 src/wp-includes/class-wp-script-modules.php | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index b1544813bff27..ad5cdcccc2cf2 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -34,15 +34,11 @@ class WP_Script_Modules {
 	 * Holds script module identifiers that have been marked for inclusion in the import map.
 	 *
 	 * A script module that appears here should be include in the import map regardless of
-	 * whether it is a dependency of another script module.
-	 *
-	 * The values in this array are always `null`. The presence of a Module IDs
-	 * as an array key marks the script module for inclusion in the import map.
-	 * Different values are reserved for possible future use.
+	 * whether it is in the dependency graph of enqueued script modules.
 	 *
 	 * @since 6.8.0
 	 *
-	 * @var array<string, null>
+	 * @var string[]
 	 */
 	private $marked_for_inclusion = array();
 
@@ -176,7 +172,7 @@ public function enqueue( string $id, string $src = '', array $deps = array(), $v
 	 * @param string $id The identifier of the script module.
 	 */
 	public function include_in_import_map( string $id ) {
-		$this->marked_for_inclusion[ $id ] = null;
+		$this->marked_for_inclusion[] = $id;
 	}
 
 	/**
@@ -309,7 +305,7 @@ public function print_import_map() {
 	 */
 	private function get_import_map(): array {
 		$imports           = array();
-		$script_module_ids = array_unique( array_keys( $this->marked_for_inclusion ) + array_keys( $this->get_marked_for_enqueue() ) );
+		$script_module_ids = $this->marked_for_inclusion + array_keys( $this->get_marked_for_enqueue() );
 
 		foreach ( $this->get_dependencies( $script_module_ids ) as $id => $script_module ) {
 			$src = $this->get_src( $id );
@@ -318,7 +314,7 @@ private function get_import_map(): array {
 			}
 			$imports[ $id ] = $src;
 		}
-		foreach ( $this->marked_for_inclusion as $id => $_ ) {
+		foreach ( $this->marked_for_inclusion as $id ) {
 			$src = $this->get_src( $id );
 			if ( null === $src ) {
 				continue;

From 7fc42d2ac79f39cd60f2b863d015f389a0e66209 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Tue, 17 Dec 2024 09:57:28 +0100
Subject: [PATCH 05/42] Replace excessively prescriptive comment

---
 src/wp-includes/class-wp-script-modules.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index ad5cdcccc2cf2..0a1408d003248 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -163,9 +163,9 @@ public function enqueue( string $id, string $src = '', array $deps = array(), $v
 	/**
 	 * Marks the script module for inclusion in the import map.
 	 *
-	 * Script Modules can rely on the script module dependency graph to include script modules
-	 * in the import map. This method makes it possible to mark a script module for inclusion
-	 * in the import map without relying on the script module dependency graph.
+	 * This method is intended for use outside of the script module dependency system.
+	 * It's recommended that script modules rely on the script module dependency system
+	 * to manage the import map.
 	 *
 	 * @since 6.8.0
 	 *

From 5144a90a31ac95d7e1e7c26f27fd64fff159817f Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Tue, 17 Dec 2024 10:20:04 +0100
Subject: [PATCH 06/42] Add test for correct merge with regular dependencies

---
 .../tests/script-modules/wpScriptModules.php  | 48 ++++++++++++++++++-
 1 file changed, 47 insertions(+), 1 deletion(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index ce757018631f9..f60666c6b8c52 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -912,7 +912,7 @@ public static function data_invalid_script_module_data(): array {
 	/**
 	 * @ticket 61500
 	 */
-	public function test_added_module_appears_in_importmap() {
+	public function test_included_module_appears_in_importmap() {
 		$this->script_modules->register( 'dependency', '/dep.js' );
 		$this->script_modules->register( 'example', '/example.js', array( 'dependency' ) );
 
@@ -927,7 +927,53 @@ public function test_added_module_appears_in_importmap() {
 		$this->assertSame( array(), $this->get_preloaded_script_modules() );
 
 		$import_map = $this->get_import_map();
+		$this->assertCount( 2, $import_map );
 		$this->assertArrayHasKey( 'example', $import_map );
 		$this->assertArrayHasKey( 'dependency', $import_map );
 	}
+
+	/**
+	 * @ticket 61500
+	 */
+	public function test_included_modules_concat_With_enqueued_dependencies() {
+		$this->script_modules->register( 'dependency-enqueued', '/dep.js' );
+		$this->script_modules->register(
+			'enqueued',
+			'/example.js',
+			array(
+				array(
+					'id'     => 'dependency-enqueued',
+					'import' => 'dynamic',
+				),
+			)
+		);
+		$this->script_modules->enqueue( 'enqueued' );
+
+		$this->script_modules->register( 'dependency', '/dep.js' );
+		$this->script_modules->register( 'example', '/example.js', array( 'dependency' ) );
+
+		// Only dependency-enqueued should be printed.
+		$enqueued = $this->get_enqueued_script_modules();
+		$this->assertCount( 1, $enqueued );
+		$this->assertArrayHasKey( 'enqueued', $enqueued );
+		$this->assertSame( array(), $this->get_preloaded_script_modules() );
+
+		$import_map = $this->get_import_map();
+		$this->assertCount( 1, $import_map );
+		$this->assertArrayHasKey( 'dependency-enqueued', $import_map );
+
+		// After including, the importmap should be populated.
+		$this->script_modules->include_in_import_map( 'example' );
+
+		$enqueued = $this->get_enqueued_script_modules();
+		$this->assertCount( 1, $enqueued );
+		$this->assertArrayHasKey( 'enqueued', $enqueued );
+		$this->assertSame( array(), $this->get_preloaded_script_modules() );
+
+		$import_map = $this->get_import_map();
+		$this->assertCount( 3, $import_map );
+		$this->assertArrayHasKey( 'dependency-enqueued', $import_map );
+		$this->assertArrayHasKey( 'dependency', $import_map );
+		$this->assertArrayHasKey( 'example', $import_map );
+	}
 }

From d83ea4b181431ac6b96c2ecc154a4513d91124be Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Tue, 17 Dec 2024 10:20:47 +0100
Subject: [PATCH 07/42] Fix overwriting array keys

The + operator merges arrays with key overwriting.
array_merge renumbers numeric arrays, the desired behavior in this case.
---
 src/wp-includes/class-wp-script-modules.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 0a1408d003248..e41d1004350c9 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -305,7 +305,7 @@ public function print_import_map() {
 	 */
 	private function get_import_map(): array {
 		$imports           = array();
-		$script_module_ids = $this->marked_for_inclusion + array_keys( $this->get_marked_for_enqueue() );
+		$script_module_ids = array_merge( $this->marked_for_inclusion, array_keys( $this->get_marked_for_enqueue() ) );
 
 		foreach ( $this->get_dependencies( $script_module_ids ) as $id => $script_module ) {
 			$src = $this->get_src( $id );

From 9125683c874c5bec3e326ba9716f27f783f39c96 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 19 Dec 2024 10:15:16 +0100
Subject: [PATCH 08/42] Working proposal with caveats

This works, but it only works as long as scripts are printed before the importmap is printed.
That is undesireable sometimes. An alternate approach may be to invert this scheme and have
script modules inspect enqueued and printed scripts before printing the importmap.
---
 src/wp-includes/class-wp-script-modules.php | 35 ++++++-----
 src/wp-includes/class-wp-scripts.php        | 69 +++++++++++++++++++++
 2 files changed, 87 insertions(+), 17 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index e41d1004350c9..3cb407505070f 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -212,18 +212,18 @@ public function deregister( string $id ) {
 	 * @since 6.5.0
 	 */
 	public function add_hooks() {
-		$position = wp_is_block_theme() ? 'wp_head' : 'wp_footer';
-		add_action( $position, array( $this, 'print_import_map' ) );
-		add_action( $position, array( $this, 'print_enqueued_script_modules' ) );
+		$position = wp_is_block_theme() ? 'wp_head' : 'wp_print_footer_scripts';
 		add_action( $position, array( $this, 'print_script_module_preloads' ) );
+		add_action( 'wp_print_footer_scripts', array( $this, 'print_import_map' ) );
+		add_action( 'wp_print_footer_scripts', array( $this, 'print_enqueued_script_modules' ) );
 
-		add_action( 'admin_print_footer_scripts', array( $this, 'print_import_map' ) );
-		add_action( 'admin_print_footer_scripts', array( $this, 'print_enqueued_script_modules' ) );
-		add_action( 'admin_print_footer_scripts', array( $this, 'print_script_module_preloads' ) );
+		add_action( 'admin_print_footer_scripts', array( $this, 'print_import_map' ), 20 );
+		add_action( 'admin_print_footer_scripts', array( $this, 'print_enqueued_script_modules' ), 20 );
+		add_action( 'admin_print_footer_scripts', array( $this, 'print_script_module_preloads' ), 20 );
 
-		add_action( 'wp_footer', array( $this, 'print_script_module_data' ) );
+		add_action( 'wp_print_footer_scripts', array( $this, 'print_script_module_data' ) );
 		add_action( 'admin_print_footer_scripts', array( $this, 'print_script_module_data' ) );
-		add_action( 'wp_footer', array( $this, 'print_a11y_script_module_html' ), 20 );
+		add_action( 'wp_print_footer_scripts', array( $this, 'print_a11y_script_module_html' ), 20 );
 		add_action( 'admin_print_footer_scripts', array( $this, 'print_a11y_script_module_html' ), 20 );
 	}
 
@@ -259,20 +259,21 @@ public function print_enqueued_script_modules() {
 	 * @since 6.5.0
 	 */
 	public function print_script_module_preloads() {
-		foreach ( $this->get_dependencies( array_keys( $this->get_marked_for_enqueue() ), array( 'static' ) ) as $id => $script_module ) {
+		$enqueued    = array_keys( $this->get_marked_for_enqueue() );
+		$static_deps = array_keys( $this->get_dependencies( $enqueued, array( 'static' ) ) );
+		$preloads    = array_unique( array_merge( $enqueued, $static_deps ) );
+
+		foreach ( $preloads as $id ) {
 			$src = $this->get_src( $id );
 			if ( null === $src ) {
 				continue;
 			}
 
-			// Don't preload if it's marked for enqueue.
-			if ( true !== $script_module['enqueue'] ) {
-				echo sprintf(
-					'<link rel="modulepreload" href="%s" id="%s">',
-					esc_url( $src ),
-					esc_attr( $id . '-js-modulepreload' )
-				);
-			}
+			echo sprintf(
+				'<link rel="modulepreload" href="%s" id="%s">',
+				esc_url( $src ),
+				esc_attr( $id . '-js-modulepreload' )
+			);
 		}
 	}
 
diff --git a/src/wp-includes/class-wp-scripts.php b/src/wp-includes/class-wp-scripts.php
index 77dff94c0497a..971e4399e4490 100644
--- a/src/wp-includes/class-wp-scripts.php
+++ b/src/wp-includes/class-wp-scripts.php
@@ -150,6 +150,58 @@ public function __construct() {
 		add_action( 'init', array( $this, 'init' ), 0 );
 	}
 
+	/**
+	 * Register an item.
+	 *
+	 * Registers the item if no item of that name already exists.
+	 *
+	 * This method is subclassed here in order to add special handling for script module
+	 * dependencies.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @see WP_Dependencies::add()
+	 *
+	 * @param string           $handle Name of the item. Should be unique.
+	 * @param string|false     $src    Full URL of the item, or path of the item relative
+	 *                                 to the WordPress root directory. If source is set to false,
+	 *                                 the item is an alias of other items it depends on.
+	 * @param (string|array{type: string, id: string})[]         $deps   Optional. An array of registered item handles this item depends on.
+	 *                                 Default empty array.
+	 * @param string|bool|null $ver    Optional. String specifying item version number, if it has one,
+	 *                                 which is added to the URL as a query string for cache busting purposes.
+	 *                                 If version is set to false, a version number is automatically added
+	 *                                 equal to current installed WordPress version.
+	 *                                 If set to null, no version is added.
+	 * @param mixed            $args   Optional. Custom property of the item. NOT the class property $args.
+	 *                                 Examples: $media, $in_footer.
+	 * @return bool Whether the item has been registered. True on success, false on failure.
+	 */
+	public function add( $handle, $src, $deps = array(), $ver = false, $args = null ) {
+		$module_deps = array();
+		$script_deps = array();
+		if ( array() !== $deps ) {
+			foreach ( $deps as $dep ) {
+				if ( is_string( $dep ) ) {
+					$script_deps[] = $dep;
+				} elseif (
+					isset( $dep['type'], $dep['id'] ) &&
+					$dep['type'] === 'module' &&
+					is_string( $dep['id'] )
+				) {
+					$module_deps[] = $dep['id'];
+				}
+			}
+		}
+		if ( ! parent::add( $handle, $src, $script_deps, $ver, $args ) ) {
+			return false;
+		}
+		if ( array() !== $module_deps ) {
+			$this->add_data( $handle, 'module_deps', $module_deps );
+		}
+		return true;
+	}
+
 	/**
 	 * Initialize the class.
 	 *
@@ -231,6 +283,20 @@ public function print_extra_script( $handle, $display = true ) {
 		return true;
 	}
 
+	/**
+	 * @todo not sure I like this…
+	 */
+	public function add_script_module_dependencies_to_import_map( $handle ) {
+		$module_deps = $this->get_data( $handle, 'module_deps' );
+		if ( ! $module_deps ) {
+			return;
+		}
+
+		foreach ( $module_deps as $module_dep ) {
+			wp_script_modules()->include_in_import_map( $module_dep );
+		}
+	}
+
 	/**
 	 * Checks whether all dependents of a given handle are in the footer.
 	 *
@@ -365,6 +431,7 @@ public function do_item( $handle, $group = false ) {
 				_print_scripts();
 				$this->reset();
 			} elseif ( $this->in_default_dir( $filtered_src ) && ! $conditional ) {
+				$this->add_script_module_dependencies_to_import_map( $handle );
 				$this->print_code     .= $this->print_extra_script( $handle, false );
 				$this->concat         .= "$handle,";
 				$this->concat_version .= "$handle$ver";
@@ -375,6 +442,8 @@ public function do_item( $handle, $group = false ) {
 			}
 		}
 
+		$this->add_script_module_dependencies_to_import_map( $handle );
+
 		$has_conditional_data = $conditional && $this->get_data( $handle, 'data' );
 
 		if ( $has_conditional_data ) {

From 5ddc2dda824eb9c03bf7782fd8a9f5515217fb24 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 19 Dec 2024 10:57:19 +0100
Subject: [PATCH 09/42] Revert preveious approach at module dependencies

---
 src/wp-includes/class-wp-script-modules.php | 35 ++++++++++-----------
 src/wp-includes/class-wp-scripts.php        | 17 ----------
 2 files changed, 17 insertions(+), 35 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 3cb407505070f..e41d1004350c9 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -212,18 +212,18 @@ public function deregister( string $id ) {
 	 * @since 6.5.0
 	 */
 	public function add_hooks() {
-		$position = wp_is_block_theme() ? 'wp_head' : 'wp_print_footer_scripts';
+		$position = wp_is_block_theme() ? 'wp_head' : 'wp_footer';
+		add_action( $position, array( $this, 'print_import_map' ) );
+		add_action( $position, array( $this, 'print_enqueued_script_modules' ) );
 		add_action( $position, array( $this, 'print_script_module_preloads' ) );
-		add_action( 'wp_print_footer_scripts', array( $this, 'print_import_map' ) );
-		add_action( 'wp_print_footer_scripts', array( $this, 'print_enqueued_script_modules' ) );
 
-		add_action( 'admin_print_footer_scripts', array( $this, 'print_import_map' ), 20 );
-		add_action( 'admin_print_footer_scripts', array( $this, 'print_enqueued_script_modules' ), 20 );
-		add_action( 'admin_print_footer_scripts', array( $this, 'print_script_module_preloads' ), 20 );
+		add_action( 'admin_print_footer_scripts', array( $this, 'print_import_map' ) );
+		add_action( 'admin_print_footer_scripts', array( $this, 'print_enqueued_script_modules' ) );
+		add_action( 'admin_print_footer_scripts', array( $this, 'print_script_module_preloads' ) );
 
-		add_action( 'wp_print_footer_scripts', array( $this, 'print_script_module_data' ) );
+		add_action( 'wp_footer', array( $this, 'print_script_module_data' ) );
 		add_action( 'admin_print_footer_scripts', array( $this, 'print_script_module_data' ) );
-		add_action( 'wp_print_footer_scripts', array( $this, 'print_a11y_script_module_html' ), 20 );
+		add_action( 'wp_footer', array( $this, 'print_a11y_script_module_html' ), 20 );
 		add_action( 'admin_print_footer_scripts', array( $this, 'print_a11y_script_module_html' ), 20 );
 	}
 
@@ -259,21 +259,20 @@ public function print_enqueued_script_modules() {
 	 * @since 6.5.0
 	 */
 	public function print_script_module_preloads() {
-		$enqueued    = array_keys( $this->get_marked_for_enqueue() );
-		$static_deps = array_keys( $this->get_dependencies( $enqueued, array( 'static' ) ) );
-		$preloads    = array_unique( array_merge( $enqueued, $static_deps ) );
-
-		foreach ( $preloads as $id ) {
+		foreach ( $this->get_dependencies( array_keys( $this->get_marked_for_enqueue() ), array( 'static' ) ) as $id => $script_module ) {
 			$src = $this->get_src( $id );
 			if ( null === $src ) {
 				continue;
 			}
 
-			echo sprintf(
-				'<link rel="modulepreload" href="%s" id="%s">',
-				esc_url( $src ),
-				esc_attr( $id . '-js-modulepreload' )
-			);
+			// Don't preload if it's marked for enqueue.
+			if ( true !== $script_module['enqueue'] ) {
+				echo sprintf(
+					'<link rel="modulepreload" href="%s" id="%s">',
+					esc_url( $src ),
+					esc_attr( $id . '-js-modulepreload' )
+				);
+			}
 		}
 	}
 
diff --git a/src/wp-includes/class-wp-scripts.php b/src/wp-includes/class-wp-scripts.php
index 971e4399e4490..5808d2d8927f1 100644
--- a/src/wp-includes/class-wp-scripts.php
+++ b/src/wp-includes/class-wp-scripts.php
@@ -283,20 +283,6 @@ public function print_extra_script( $handle, $display = true ) {
 		return true;
 	}
 
-	/**
-	 * @todo not sure I like this…
-	 */
-	public function add_script_module_dependencies_to_import_map( $handle ) {
-		$module_deps = $this->get_data( $handle, 'module_deps' );
-		if ( ! $module_deps ) {
-			return;
-		}
-
-		foreach ( $module_deps as $module_dep ) {
-			wp_script_modules()->include_in_import_map( $module_dep );
-		}
-	}
-
 	/**
 	 * Checks whether all dependents of a given handle are in the footer.
 	 *
@@ -431,7 +417,6 @@ public function do_item( $handle, $group = false ) {
 				_print_scripts();
 				$this->reset();
 			} elseif ( $this->in_default_dir( $filtered_src ) && ! $conditional ) {
-				$this->add_script_module_dependencies_to_import_map( $handle );
 				$this->print_code     .= $this->print_extra_script( $handle, false );
 				$this->concat         .= "$handle,";
 				$this->concat_version .= "$handle$ver";
@@ -442,8 +427,6 @@ public function do_item( $handle, $group = false ) {
 			}
 		}
 
-		$this->add_script_module_dependencies_to_import_map( $handle );
-
 		$has_conditional_data = $conditional && $this->get_data( $handle, 'data' );
 
 		if ( $has_conditional_data ) {

From 9e976bb24e9b932213e46b4a4b975c67d57c4581 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 19 Dec 2024 11:37:50 +0100
Subject: [PATCH 10/42] Inspect wp_scripts and extract module deps from scripts
 on the page

---
 src/wp-includes/class-wp-script-modules.php | 59 ++++++++++-----------
 1 file changed, 29 insertions(+), 30 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index e41d1004350c9..4aae4853e2e67 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -30,18 +30,6 @@ class WP_Script_Modules {
 	 */
 	private $enqueued_before_registered = array();
 
-	/**
-	 * Holds script module identifiers that have been marked for inclusion in the import map.
-	 *
-	 * A script module that appears here should be include in the import map regardless of
-	 * whether it is in the dependency graph of enqueued script modules.
-	 *
-	 * @since 6.8.0
-	 *
-	 * @var string[]
-	 */
-	private $marked_for_inclusion = array();
-
 	/**
 	 * Tracks whether the @wordpress/a11y script module is available.
 	 *
@@ -160,21 +148,6 @@ public function enqueue( string $id, string $src = '', array $deps = array(), $v
 		}
 	}
 
-	/**
-	 * Marks the script module for inclusion in the import map.
-	 *
-	 * This method is intended for use outside of the script module dependency system.
-	 * It's recommended that script modules rely on the script module dependency system
-	 * to manage the import map.
-	 *
-	 * @since 6.8.0
-	 *
-	 * @param string $id The identifier of the script module.
-	 */
-	public function include_in_import_map( string $id ) {
-		$this->marked_for_inclusion[] = $id;
-	}
-
 	/**
 	 * Unmarks the script module so it will no longer be enqueued in the page.
 	 *
@@ -299,13 +272,39 @@ public function print_import_map() {
 	 *
 	 * @since 6.5.0
 	 *
+	 * @global WP_Dependencies $wp_scripts
+	 *
 	 * @return array Array with an `imports` key mapping to an array of script
 	 *               module identifiers and their respective URLs, including
 	 *               the version query.
 	 */
 	private function get_import_map(): array {
-		$imports           = array();
-		$script_module_ids = array_merge( $this->marked_for_inclusion, array_keys( $this->get_marked_for_enqueue() ) );
+		global $wp_scripts;
+		$script_module_ids = array();
+		if ( $wp_scripts instanceof WP_Dependencies ) {
+			foreach ( $wp_scripts->registered as $dependency ) {
+				$handle = $dependency->handle;
+
+				if (
+					! $wp_scripts->query( $handle, 'done' ) &&
+					! $wp_scripts->query( $handle, 'to_do' ) &&
+					! $wp_scripts->query( $handle, 'enqueued' )
+				) {
+					continue;
+				}
+
+				$module_deps = $wp_scripts->get_data( $handle, 'module_deps' );
+				if ( ! is_array( $module_deps ) ) {
+					continue;
+				}
+
+				foreach ( $module_deps as $id ) {
+					$script_module_ids[] = $id;
+				}
+			}
+		}
+
+		$script_module_ids = array_merge( $script_module_ids, array_keys( $this->get_marked_for_enqueue() ) );
 
 		foreach ( $this->get_dependencies( $script_module_ids ) as $id => $script_module ) {
 			$src = $this->get_src( $id );
@@ -314,7 +313,7 @@ private function get_import_map(): array {
 			}
 			$imports[ $id ] = $src;
 		}
-		foreach ( $this->marked_for_inclusion as $id ) {
+		foreach ( $script_module_ids as $id ) {
 			$src = $this->get_src( $id );
 			if ( null === $src ) {
 				continue;

From 591e3b5f664ab00675dd157386cf994b49b60ae9 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 19 Dec 2024 12:03:19 +0100
Subject: [PATCH 11/42] Fix regression printing enqueued modules in importmap

---
 src/wp-includes/class-wp-script-modules.php | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 4aae4853e2e67..09d614717d76f 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -304,9 +304,8 @@ private function get_import_map(): array {
 			}
 		}
 
-		$script_module_ids = array_merge( $script_module_ids, array_keys( $this->get_marked_for_enqueue() ) );
-
-		foreach ( $this->get_dependencies( $script_module_ids ) as $id => $script_module ) {
+		$imports = array();
+		foreach ( $this->get_dependencies( array_merge( $script_module_ids, array_keys( $this->get_marked_for_enqueue() ) ) ) as $id => $script_module ) {
 			$src = $this->get_src( $id );
 			if ( null === $src ) {
 				continue;

From d1d8c43a2e7a8192fc00d7a153685fb682cd9b31 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 19 Dec 2024 12:09:33 +0100
Subject: [PATCH 12/42] Check for WP_Scripts instance

---
 src/wp-includes/class-wp-script-modules.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 09d614717d76f..c286ae0e96ba4 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -281,7 +281,7 @@ public function print_import_map() {
 	private function get_import_map(): array {
 		global $wp_scripts;
 		$script_module_ids = array();
-		if ( $wp_scripts instanceof WP_Dependencies ) {
+		if ( $wp_scripts instanceof WP_Scripts ) {
 			foreach ( $wp_scripts->registered as $dependency ) {
 				$handle = $dependency->handle;
 

From 10c3a02924e4c36332744d70cdad3c106d645175 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 19 Dec 2024 13:43:49 +0100
Subject: [PATCH 13/42] Fix possible unset module id in script modules

---
 src/wp-includes/class-wp-script-modules.php | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index c286ae0e96ba4..bbc7b82fdc4ae 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -359,6 +359,9 @@ private function get_dependencies( array $ids, array $import_types = array( 'sta
 		return array_reduce(
 			$ids,
 			function ( $dependency_script_modules, $id ) use ( $import_types ) {
+				if ( ! isset( $this->registered[ $id ]['dependencies'] ) ) {
+					return $dependency_script_modules;
+				}
 				$dependencies = array();
 				foreach ( $this->registered[ $id ]['dependencies'] as $dependency ) {
 					if (

From a444ffabf940aa8c6d7cec3f55399ca880d07539 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 19 Dec 2024 13:43:58 +0100
Subject: [PATCH 14/42] Fix lint

---
 src/wp-includes/class-wp-scripts.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/wp-includes/class-wp-scripts.php b/src/wp-includes/class-wp-scripts.php
index 5808d2d8927f1..29ae293350974 100644
--- a/src/wp-includes/class-wp-scripts.php
+++ b/src/wp-includes/class-wp-scripts.php
@@ -186,7 +186,7 @@ public function add( $handle, $src, $deps = array(), $ver = false, $args = null
 					$script_deps[] = $dep;
 				} elseif (
 					isset( $dep['type'], $dep['id'] ) &&
-					$dep['type'] === 'module' &&
+					'module' === $dep['type'] &&
 					is_string( $dep['id'] )
 				) {
 					$module_deps[] = $dep['id'];

From b0f579b8b1fefb61d9120616410770621c432dd5 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 19 Dec 2024 18:07:15 +0100
Subject: [PATCH 15/42] Update and improve tests with classic scripts

---
 .../tests/script-modules/wpScriptModules.php  | 126 +++++++++++++-----
 1 file changed, 95 insertions(+), 31 deletions(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index f60666c6b8c52..a44317d598ecc 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -27,8 +27,38 @@ public function set_up() {
 		parent::set_up();
 		// Set up the WP_Script_Modules instance.
 		$this->script_modules = new WP_Script_Modules();
+		unset( $GLOBALS['wp_scripts'] );
 	}
 
+	private static $wp_scripts;
+	private static $wp_scripts_was_set = false;
+
+	public static function set_up_before_class() {
+		parent::set_up_before_class();
+
+		// If the global is set, store it for restoring when done testing.
+		static::$wp_scripts_was_set = array_key_exists( 'wp_scripts', $GLOBALS );
+		if ( static::$wp_scripts_was_set ) {
+			static::$wp_scripts = $GLOBALS['wp_scripts'];
+			unset( $GLOBALS['wp_scripts'] );
+		}
+	}
+
+	public static function tear_down_after_class() {
+		// Restore the global if it was set before running this set of tests.
+		if ( static::$wp_scripts_was_set ) {
+			$GLOBALS['wp_scripts'] = static::$wp_scripts;
+		}
+
+		parent::tear_down_after_class();
+	}
+
+	public function clean_up_global_scope() {
+		unset( $GLOBALS['wp_scripts'] );
+		parent::clean_up_global_scope();
+	}
+
+
 	/**
 	 * Gets a list of the enqueued script modules.
 	 *
@@ -917,63 +947,97 @@ public function test_included_module_appears_in_importmap() {
 		$this->script_modules->register( 'example', '/example.js', array( 'dependency' ) );
 
 		// Nothing printed now.
-		$this->assertSame( array(), $this->get_enqueued_script_modules() );
-		$this->assertSame( array(), $this->get_preloaded_script_modules() );
-		$this->assertSame( array(), $this->get_import_map() );
+		$this->assertSame( array(), $this->get_enqueued_script_modules(), 'Initial enqueued script modules was wrong.' );
+		$this->assertSame( array(), $this->get_preloaded_script_modules(), 'Initial module preloads was wrong.' );
+		$this->assertSame( array(), $this->get_import_map(), 'Initial import map was wrong.' );
+
+		// Enqueuing a script with a module dependency should add it to the import map.
+		wp_enqueue_script(
+			'classic',
+			'/classic.js',
+			array(
+				'classic-dependency',
+				array(
+					'type' => 'module',
+					'id'   => 'example',
+				),
+			)
+		);
 
-		// After including, the importmap should be populated.
-		$this->script_modules->include_in_import_map( 'example' );
-		$this->assertSame( array(), $this->get_enqueued_script_modules() );
-		$this->assertSame( array(), $this->get_preloaded_script_modules() );
+		$this->assertSame( array(), $this->get_enqueued_script_modules(), 'Final enqueued script modules was wrong.' );
+		$this->assertSame( array(), $this->get_preloaded_script_modules(), 'Final module preloads was wrong.' );
 
 		$import_map = $this->get_import_map();
-		$this->assertCount( 2, $import_map );
-		$this->assertArrayHasKey( 'example', $import_map );
-		$this->assertArrayHasKey( 'dependency', $import_map );
+		$this->assertCount( 2, $import_map, 'Final import map count was wrong.' );
+		$this->assertArrayHasKey( 'example', $import_map, 'Final missing "example" script module in import map.' );
+		$this->assertArrayHasKey( 'dependency', $import_map, 'Final missing "dependency" script module in import map.' );
 	}
 
 	/**
 	 * @ticket 61500
 	 */
 	public function test_included_modules_concat_With_enqueued_dependencies() {
-		$this->script_modules->register( 'dependency-enqueued', '/dep.js' );
-		$this->script_modules->register(
+		$this->script_modules->register( 'dependency-of-enqueued', '/dependency-of-enqueued.js' );
+		$this->script_modules->enqueue(
 			'enqueued',
-			'/example.js',
+			'/enqueued.js',
 			array(
 				array(
-					'id'     => 'dependency-enqueued',
+					'id'     => 'dependency-of-enqueued',
 					'import' => 'dynamic',
 				),
 			)
 		);
-		$this->script_modules->enqueue( 'enqueued' );
 
-		$this->script_modules->register( 'dependency', '/dep.js' );
-		$this->script_modules->register( 'example', '/example.js', array( 'dependency' ) );
+		$this->script_modules->register( 'classic-transitive-dependency', '/classic-transitive-dependency.js' );
+
+		$this->script_modules->register( 'dependency-of-not-enqueued', '/dependency-of-not-enqueued.js' );
+		$this->script_modules->register( 'not-enqueued', '/not-enqueued.js', array( 'dependency-of-not-enqueued' ) );
 
 		// Only dependency-enqueued should be printed.
 		$enqueued = $this->get_enqueued_script_modules();
-		$this->assertCount( 1, $enqueued );
-		$this->assertArrayHasKey( 'enqueued', $enqueued );
-		$this->assertSame( array(), $this->get_preloaded_script_modules() );
+		$this->assertCount( 1, $enqueued, 'Initial enqueue count was wrong.' );
+		$this->assertArrayHasKey( 'enqueued', $enqueued, 'Initial missing "enqueued" script module enqueue.' );
+		$this->assertCount( 0, $this->get_preloaded_script_modules(), 'Initial module preload count was wrong.' );
 
 		$import_map = $this->get_import_map();
-		$this->assertCount( 1, $import_map );
-		$this->assertArrayHasKey( 'dependency-enqueued', $import_map );
+		$this->assertCount( 1, $import_map, 'Initial import map count was wrong.' );
+		$this->assertArrayHasKey( 'dependency-of-enqueued', $import_map, 'Initial missing "dependency-of-enqueued" script module in import map.' );
 
-		// After including, the importmap should be populated.
-		$this->script_modules->include_in_import_map( 'example' );
+		// Enqueuing a script with a module dependency should add it to the import map.
+		wp_register_script(
+			'_test_classic-dependency_',
+			'/classic-transitive-dep.js',
+			array(
+				array(
+					'type' => 'module',
+					'id'   => 'classic-transitive-dependency',
+				),
+			)
+		);
+		wp_enqueue_script(
+			'_test_classic_',
+			'/classic.js',
+			array(
+				'_test_classic-dependency_',
+				array(
+					'type' => 'module',
+					'id'   => 'not-enqueued',
+				),
+			)
+		);
 
 		$enqueued = $this->get_enqueued_script_modules();
-		$this->assertCount( 1, $enqueued );
-		$this->assertArrayHasKey( 'enqueued', $enqueued );
-		$this->assertSame( array(), $this->get_preloaded_script_modules() );
+		$this->assertCount( 1, $enqueued, 'Final enqueue count was wrong.' );
+		$this->assertArrayHasKey( 'enqueued', $enqueued, 'Final missing "enqueued" script module enqueue.' );
+
+		$this->assertCount( 0, $this->get_preloaded_script_modules(), 'Final module preload count was wrong.' );
 
 		$import_map = $this->get_import_map();
-		$this->assertCount( 3, $import_map );
-		$this->assertArrayHasKey( 'dependency-enqueued', $import_map );
-		$this->assertArrayHasKey( 'dependency', $import_map );
-		$this->assertArrayHasKey( 'example', $import_map );
+		$this->assertCount( 4, $import_map, 'Final import map count was wrong.' );
+		$this->assertArrayHasKey( 'dependency-of-enqueued', $import_map, 'Final missing "dependency-of-enqueued" script module in import map.' );
+		$this->assertArrayHasKey( 'classic-transitive-dependency', $import_map, 'Final missing "classic-transitive-dependency" script module in import map.' );
+		$this->assertArrayHasKey( 'not-enqueued', $import_map, 'Final missing "not-enqueued" script module in import map.' );
+		$this->assertArrayHasKey( 'dependency-of-not-enqueued', $import_map, 'Final missing "dependency-of-not-enqueued" script module in import map.' );
 	}
 }

From 8366f451c0c6a7a926c4e76e5e4606f5d8e7467d Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 19 Dec 2024 18:07:31 +0100
Subject: [PATCH 16/42] Improve variable name and array push of many values

---
 src/wp-includes/class-wp-script-modules.php | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index bbc7b82fdc4ae..08bf9d06183a3 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -280,7 +280,7 @@ public function print_import_map() {
 	 */
 	private function get_import_map(): array {
 		global $wp_scripts;
-		$script_module_ids = array();
+		$classic_script_module_dependencies = array();
 		if ( $wp_scripts instanceof WP_Scripts ) {
 			foreach ( $wp_scripts->registered as $dependency ) {
 				$handle = $dependency->handle;
@@ -294,25 +294,22 @@ private function get_import_map(): array {
 				}
 
 				$module_deps = $wp_scripts->get_data( $handle, 'module_deps' );
-				if ( ! is_array( $module_deps ) ) {
+				if ( ! $module_deps ) {
 					continue;
 				}
-
-				foreach ( $module_deps as $id ) {
-					$script_module_ids[] = $id;
-				}
+				array_push( $classic_script_module_dependencies, ...$module_deps );
 			}
 		}
 
 		$imports = array();
-		foreach ( $this->get_dependencies( array_merge( $script_module_ids, array_keys( $this->get_marked_for_enqueue() ) ) ) as $id => $script_module ) {
+		foreach ( $this->get_dependencies( array_merge( $classic_script_module_dependencies, array_keys( $this->get_marked_for_enqueue() ) ) ) as $id => $script_module ) {
 			$src = $this->get_src( $id );
 			if ( null === $src ) {
 				continue;
 			}
 			$imports[ $id ] = $src;
 		}
-		foreach ( $script_module_ids as $id ) {
+		foreach ( $classic_script_module_dependencies as $id ) {
 			$src = $this->get_src( $id );
 			if ( null === $src ) {
 				continue;

From 45cacbb26723b8c71036ccf5e612f9e0709ca154 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 19 Dec 2024 18:15:57 +0100
Subject: [PATCH 17/42] Remove a loop from importmap checking

---
 src/wp-includes/class-wp-script-modules.php | 27 ++++++++++-----------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 08bf9d06183a3..e7b9ad2482280 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -280,7 +280,10 @@ public function print_import_map() {
 	 */
 	private function get_import_map(): array {
 		global $wp_scripts;
-		$classic_script_module_dependencies = array();
+
+		$imports = array();
+
+		$classic_script_dependencies = array();
 		if ( $wp_scripts instanceof WP_Scripts ) {
 			foreach ( $wp_scripts->registered as $dependency ) {
 				$handle = $dependency->handle;
@@ -297,19 +300,18 @@ private function get_import_map(): array {
 				if ( ! $module_deps ) {
 					continue;
 				}
-				array_push( $classic_script_module_dependencies, ...$module_deps );
+				foreach ( $module_deps as $id ) {
+					$src = $this->get_src( $id );
+					if ( null === $src ) {
+						continue;
+					}
+					$imports[ $id ]                = $src;
+					$classic_script_dependencies[] = $id;
+				}
 			}
 		}
 
-		$imports = array();
-		foreach ( $this->get_dependencies( array_merge( $classic_script_module_dependencies, array_keys( $this->get_marked_for_enqueue() ) ) ) as $id => $script_module ) {
-			$src = $this->get_src( $id );
-			if ( null === $src ) {
-				continue;
-			}
-			$imports[ $id ] = $src;
-		}
-		foreach ( $classic_script_module_dependencies as $id ) {
+		foreach ( $this->get_dependencies( array_merge( $classic_script_dependencies, array_keys( $this->get_marked_for_enqueue() ) ) ) as $id => $script_module ) {
 			$src = $this->get_src( $id );
 			if ( null === $src ) {
 				continue;
@@ -356,9 +358,6 @@ private function get_dependencies( array $ids, array $import_types = array( 'sta
 		return array_reduce(
 			$ids,
 			function ( $dependency_script_modules, $id ) use ( $import_types ) {
-				if ( ! isset( $this->registered[ $id ]['dependencies'] ) ) {
-					return $dependency_script_modules;
-				}
 				$dependencies = array();
 				foreach ( $this->registered[ $id ]['dependencies'] as $dependency ) {
 					if (

From b77dbc7bfc24fc65e5742455a72e469c709a276f Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Wed, 28 Jan 2026 18:34:09 -0800
Subject: [PATCH 18/42] Remove merge conflict markers

---
 tests/phpunit/tests/script-modules/wpScriptModules.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index f942abcb0388d..137b9c59ad83f 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -2016,7 +2016,6 @@ public static function data_invalid_script_module_data(): array {
 	}
 
 	/**
-<<<<<<< HEAD
 	 * @ticket 61500
 	 */
 	public function test_included_module_appears_in_importmap() {
@@ -2116,7 +2115,9 @@ public function test_included_modules_concat_With_enqueued_dependencies() {
 		$this->assertArrayHasKey( 'classic-transitive-dependency', $import_map, 'Final missing "classic-transitive-dependency" script module in import map.' );
 		$this->assertArrayHasKey( 'not-enqueued', $import_map, 'Final missing "not-enqueued" script module in import map.' );
 		$this->assertArrayHasKey( 'dependency-of-not-enqueued', $import_map, 'Final missing "dependency-of-not-enqueued" script module in import map.' );
-=======
+	}
+
+	/**
 	 * Tests various ways of printing and dependency ordering of script modules.
 	 *
 	 * This ensures that the global function aliases pass all the same parameters as the class methods.
@@ -2513,6 +2514,5 @@ public function test_missing_script_module_dependency_triggers_incorrect_usage()
 			'The script module with the ID "main-module" was enqueued with dependencies that are not registered: missing-mod-dep',
 			$this->caught_doing_it_wrong[ $expected_incorrect_usage ]
 		);
->>>>>>> 35307740e87f52425fb6736055f7d5b91573f842
 	}
 }

From 1d12174ad79033f2b0248f66f9d288b2a0a574c6 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Wed, 28 Jan 2026 18:54:24 -0800
Subject: [PATCH 19/42] Fix test_included_module_appears_in_importmap

---
 src/wp-includes/class-wp-script-modules.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 098d0a062b787..db186c0ce5494 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -565,7 +565,13 @@ private function get_import_map(): array {
 			}
 		}
 
-		foreach ( array_keys( $this->get_dependencies( array_merge( $classic_script_dependencies, $this->queue ) ) ) as $id ) {
+		$ids = array_unique(
+			array_merge(
+				$classic_script_dependencies,
+				array_keys( $this->get_dependencies( array_merge( $classic_script_dependencies, $this->queue ) ) )
+			)
+		);
+		foreach ( $ids as $id ) {
 			$src = $this->get_src( $id );
 			if ( '' !== $src && null !== $src ) {
 				$imports[ $id ] = $src;

From 64e67b88aad925aa7778141f7f13f6abc9ac8e00 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Wed, 28 Jan 2026 19:07:28 -0800
Subject: [PATCH 20/42] Fix
 test_included_modules_concat_with_enqueued_dependencies

The test `test_included_modules_concat_with_enqueued_dependencies` in `Tests_Script_Modules_WpScriptModules` was failing because it attempts to inspect the enqueued script modules twice. The first inspection triggers the printing of modules, which marks them as "done" internally in `WP_Script_Modules`. Consequently, the second inspection returns an empty set of modules, leading to assertion failures.

This commit uses `ReflectionClass` to reset the private `$done` property of the `WP_Script_Modules` instance between the two inspections, ensuring the modules can be processed and verified a second time.

It also fixes a typo in the test method name.

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
---
 tests/phpunit/tests/script-modules/wpScriptModules.php | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index 137b9c59ad83f..d64056e40086e 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -2052,7 +2052,7 @@ public function test_included_module_appears_in_importmap() {
 	/**
 	 * @ticket 61500
 	 */
-	public function test_included_modules_concat_With_enqueued_dependencies() {
+	public function test_included_modules_concat_with_enqueued_dependencies() {
 		$this->script_modules->register( 'dependency-of-enqueued', '/dependency-of-enqueued.js' );
 		$this->script_modules->enqueue(
 			'enqueued',
@@ -2080,6 +2080,14 @@ public function test_included_modules_concat_With_enqueued_dependencies() {
 		$this->assertCount( 1, $import_map, 'Initial import map count was wrong.' );
 		$this->assertArrayHasKey( 'dependency-of-enqueued', $import_map, 'Initial missing "dependency-of-enqueued" script module in import map.' );
 
+		// Reset the printed modules so we can check again later.
+		$reflection    = new ReflectionClass( $this->script_modules );
+		$done_property = $reflection->getProperty( 'done' );
+		if ( PHP_VERSION_ID < 80100 ) {
+			$done_property->setAccessible( true );
+		}
+		$done_property->setValue( $this->script_modules, array() );
+
 		// Enqueuing a script with a module dependency should add it to the import map.
 		wp_register_script(
 			'_test_classic-dependency_',

From f2f72a6368332efe37418d42a008b8ad98fc1da5 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Thu, 29 Jan 2026 15:29:31 -0800
Subject: [PATCH 21/42] Pass module dependencies via args insead of deps

---
 src/wp-includes/class-wp-script-modules.php   |  6 +-
 src/wp-includes/class-wp-scripts.php          | 52 ----------------
 src/wp-includes/functions.wp-scripts.php      | 60 +++++++++++--------
 .../tests/script-modules/wpScriptModules.php  | 23 +++----
 4 files changed, 46 insertions(+), 95 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index db186c0ce5494..2631d9569ed61 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -555,11 +555,11 @@ private function get_import_map(): array {
 					continue;
 				}
 
-				$module_deps = $wp_scripts->get_data( $handle, 'module_deps' );
-				if ( ! $module_deps ) {
+				$module_dependencies = $wp_scripts->get_data( $handle, 'module_dependencies' );
+				if ( ! $module_dependencies ) {
 					continue;
 				}
-				foreach ( $module_deps as $id ) {
+				foreach ( $module_dependencies as $id ) {
 					$classic_script_dependencies[] = $id;
 				}
 			}
diff --git a/src/wp-includes/class-wp-scripts.php b/src/wp-includes/class-wp-scripts.php
index 714bd98b83a36..0ed7087a93f4c 100644
--- a/src/wp-includes/class-wp-scripts.php
+++ b/src/wp-includes/class-wp-scripts.php
@@ -154,58 +154,6 @@ public function __construct() {
 		add_action( 'init', array( $this, 'init' ), 0 );
 	}
 
-	/**
-	 * Register an item.
-	 *
-	 * Registers the item if no item of that name already exists.
-	 *
-	 * This method is subclassed here in order to add special handling for script module
-	 * dependencies.
-	 *
-	 * @since 6.8.0
-	 *
-	 * @see WP_Dependencies::add()
-	 *
-	 * @param string           $handle Name of the item. Should be unique.
-	 * @param string|false     $src    Full URL of the item, or path of the item relative
-	 *                                 to the WordPress root directory. If source is set to false,
-	 *                                 the item is an alias of other items it depends on.
-	 * @param (string|array{type: string, id: string})[]         $deps   Optional. An array of registered item handles this item depends on.
-	 *                                 Default empty array.
-	 * @param string|bool|null $ver    Optional. String specifying item version number, if it has one,
-	 *                                 which is added to the URL as a query string for cache busting purposes.
-	 *                                 If version is set to false, a version number is automatically added
-	 *                                 equal to current installed WordPress version.
-	 *                                 If set to null, no version is added.
-	 * @param mixed            $args   Optional. Custom property of the item. NOT the class property $args.
-	 *                                 Examples: $media, $in_footer.
-	 * @return bool Whether the item has been registered. True on success, false on failure.
-	 */
-	public function add( $handle, $src, $deps = array(), $ver = false, $args = null ) {
-		$module_deps = array();
-		$script_deps = array();
-		if ( array() !== $deps ) {
-			foreach ( $deps as $dep ) {
-				if ( is_string( $dep ) ) {
-					$script_deps[] = $dep;
-				} elseif (
-					isset( $dep['type'], $dep['id'] ) &&
-					'module' === $dep['type'] &&
-					is_string( $dep['id'] )
-				) {
-					$module_deps[] = $dep['id'];
-				}
-			}
-		}
-		if ( ! parent::add( $handle, $src, $script_deps, $ver, $args ) ) {
-			return false;
-		}
-		if ( array() !== $module_deps ) {
-			$this->add_data( $handle, 'module_deps', $module_deps );
-		}
-		return true;
-	}
-
 	/**
 	 * Initialize the class.
 	 *
diff --git a/src/wp-includes/functions.wp-scripts.php b/src/wp-includes/functions.wp-scripts.php
index f1a9b2afd6b7c..c4a95dbbe390c 100644
--- a/src/wp-includes/functions.wp-scripts.php
+++ b/src/wp-includes/functions.wp-scripts.php
@@ -160,21 +160,22 @@ function wp_add_inline_script( $handle, $data, $position = 'after' ) {
  * @since 6.3.0 The $in_footer parameter of type boolean was overloaded to be an $args parameter of type array.
  * @since 6.9.0 The $fetchpriority parameter of type string was added to the $args parameter of type array.
  *
- * @param string                          $handle Name of the script. Should be unique.
- * @param string|false                    $src    Full URL of the script, or path of the script relative to the WordPress root directory.
- *                                                If source is set to false, script is an alias of other scripts it depends on.
- * @param string[]                        $deps   Optional. An array of registered script handles this script depends on. Default empty array.
- * @param string|bool|null                $ver    Optional. String specifying script version number, if it has one, which is added to the URL
- *                                                as a query string for cache busting purposes. If version is set to false, a version
- *                                                number is automatically added equal to current installed WordPress version.
- *                                                If set to null, no version is added.
- * @param array<string, string|bool>|bool $args   {
- *     Optional. An array of additional script loading strategies. Default empty array.
+ * @param string                                   $handle Name of the script. Should be unique.
+ * @param string|false                             $src    Full URL of the script, or path of the script relative to the WordPress root directory.
+ *                                                         If source is set to false, script is an alias of other scripts it depends on.
+ * @param string[]                                 $deps   Optional. An array of registered script handles this script depends on. Default empty array.
+ * @param string|bool|null                         $ver    Optional. String specifying script version number, if it has one, which is added to the URL
+ *                                                         as a query string for cache busting purposes. If version is set to false, a version
+ *                                                         number is automatically added equal to current installed WordPress version.
+ *                                                         If set to null, no version is added.
+ * @param array<string, string|bool|string[]>|bool $args   {
+ *     Optional. An array of extra args for the script. Default empty array.
  *     Otherwise, it may be a boolean in which case it determines whether the script is printed in the footer. Default false.
  *
- *     @type string    $strategy      Optional. If provided, may be either 'defer' or 'async'.
- *     @type bool      $in_footer     Optional. Whether to print the script in the footer. Default 'false'.
- *     @type string    $fetchpriority Optional. The fetch priority for the script. Default 'auto'.
+ *     @type string   $strategy            Optional. If provided, may be either 'defer' or 'async'.
+ *     @type bool     $in_footer           Optional. Whether to print the script in the footer. Default 'false'.
+ *     @type string   $fetchpriority       Optional. The fetch priority for the script. Default 'auto'.
+ *     @type string[] $module_dependencies Optional. IDs for module dependencies loaded via dynamic import. Default 'array()'.
  * }
  * @return bool Whether the script has been registered. True on success, false on failure.
  */
@@ -198,6 +199,9 @@ function wp_register_script( $handle, $src, $deps = array(), $ver = false, $args
 	if ( ! empty( $args['fetchpriority'] ) ) {
 		$wp_scripts->add_data( $handle, 'fetchpriority', $args['fetchpriority'] );
 	}
+	if ( ! empty( $args['module_dependencies'] ) ) {
+		$wp_scripts->add_data( $handle, 'module_dependencies', $args['module_dependencies'] );
+	}
 	return $registered;
 }
 
@@ -346,21 +350,22 @@ function wp_deregister_script( $handle ) {
  * @since 6.3.0 The $in_footer parameter of type boolean was overloaded to be an $args parameter of type array.
  * @since 6.9.0 The $fetchpriority parameter of type string was added to the $args parameter of type array.
  *
- * @param string                          $handle Name of the script. Should be unique.
- * @param string                          $src    Full URL of the script, or path of the script relative to the WordPress root directory.
- *                                                Default empty.
- * @param string[]                        $deps   Optional. An array of registered script handles this script depends on. Default empty array.
- * @param string|bool|null                $ver    Optional. String specifying script version number, if it has one, which is added to the URL
- *                                                as a query string for cache busting purposes. If version is set to false, a version
- *                                                number is automatically added equal to current installed WordPress version.
- *                                                If set to null, no version is added.
- * @param array<string, string|bool>|bool $args   {
- *     Optional. An array of additional script loading strategies. Default empty array.
+ * @param string                                   $handle Name of the script. Should be unique.
+ * @param string                                   $src    Full URL of the script, or path of the script relative to the WordPress root directory.
+ *                                                         Default empty.
+ * @param string[]                                 $deps   Optional. An array of registered script handles this script depends on. Default empty array.
+ * @param string|bool|null                         $ver    Optional. String specifying script version number, if it has one, which is added to the URL
+ *                                                         as a query string for cache busting purposes. If version is set to false, a version
+ *                                                         number is automatically added equal to current installed WordPress version.
+ *                                                         If set to null, no version is added.
+ * @param array<string, string|bool|string[]>|bool $args   {
+ *     Optional. An array of extra args for the script. Default empty array.
  *     Otherwise, it may be a boolean in which case it determines whether the script is printed in the footer. Default false.
  *
- *     @type string    $strategy      Optional. If provided, may be either 'defer' or 'async'.
- *     @type bool      $in_footer     Optional. Whether to print the script in the footer. Default 'false'.
- *     @type string    $fetchpriority Optional. The fetch priority for the script. Default 'auto'.
+ *     @type string   $strategy            Optional. If provided, may be either 'defer' or 'async'.
+ *     @type bool     $in_footer           Optional. Whether to print the script in the footer. Default 'false'.
+ *     @type string   $fetchpriority       Optional. The fetch priority for the script. Default 'auto'.
+ *     @type string[] $module_dependencies Optional. IDs for module dependencies loaded via dynamic import. Default 'array()'.
  * }
  */
 function wp_enqueue_script( $handle, $src = '', $deps = array(), $ver = false, $args = array() ) {
@@ -388,6 +393,9 @@ function wp_enqueue_script( $handle, $src = '', $deps = array(), $ver = false, $
 		if ( ! empty( $args['fetchpriority'] ) ) {
 			$wp_scripts->add_data( $_handle[0], 'fetchpriority', $args['fetchpriority'] );
 		}
+		if ( ! empty( $args['module_dependencies'] ) ) {
+			$wp_scripts->add_data( $_handle[0], 'module_dependencies', $args['module_dependencies'] );
+		}
 	}
 
 	$wp_scripts->enqueue( $handle );
diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index d64056e40086e..85c564c603e55 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -2031,12 +2031,10 @@ public function test_included_module_appears_in_importmap() {
 		wp_enqueue_script(
 			'classic',
 			'/classic.js',
+			array( 'classic-dependency' ),
+			false,
 			array(
-				'classic-dependency',
-				array(
-					'type' => 'module',
-					'id'   => 'example',
-				),
+				'module_dependencies' => array( 'example' ),
 			)
 		);
 
@@ -2092,22 +2090,19 @@ public function test_included_modules_concat_with_enqueued_dependencies() {
 		wp_register_script(
 			'_test_classic-dependency_',
 			'/classic-transitive-dep.js',
+			array(),
+			false,
 			array(
-				array(
-					'type' => 'module',
-					'id'   => 'classic-transitive-dependency',
-				),
+				'module_dependencies' => array( 'classic-transitive-dependency' ),
 			)
 		);
 		wp_enqueue_script(
 			'_test_classic_',
 			'/classic.js',
+			array( '_test_classic-dependency_' ),
+			false,
 			array(
-				'_test_classic-dependency_',
-				array(
-					'type' => 'module',
-					'id'   => 'not-enqueued',
-				),
+				'module_dependencies' => array( 'not-enqueued' ),
 			)
 		);
 

From d926e8f36b7b69e375ffc23600c9dd56460ffddb Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Thu, 29 Jan 2026 15:31:31 -0800
Subject: [PATCH 22/42] Ensure module_dependencies is an array before iterating
 over

---
 src/wp-includes/class-wp-script-modules.php | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 2631d9569ed61..2c8c5683a1097 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -556,11 +556,10 @@ private function get_import_map(): array {
 				}
 
 				$module_dependencies = $wp_scripts->get_data( $handle, 'module_dependencies' );
-				if ( ! $module_dependencies ) {
-					continue;
-				}
-				foreach ( $module_dependencies as $id ) {
-					$classic_script_dependencies[] = $id;
+				if ( is_array( $module_dependencies ) ) {
+					foreach ( $module_dependencies as $id ) {
+						$classic_script_dependencies[] = $id;
+					}
 				}
 			}
 		}

From 1a1df99ac034a803a68a520d47baa807f326248c Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Thu, 29 Jan 2026 18:28:12 -0800
Subject: [PATCH 23/42] Optimize classic script module dependency resolution

Traverse only the dependency tree of enqueued classic scripts to find module dependencies, avoiding the need to iterate over all registered scripts. This ensures that module dependencies are correctly included for all scripts in the queue (including transitive dependencies) while improving performance.

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
---
 src/wp-includes/class-wp-script-modules.php   | 26 +++++++++++++------
 .../tests/script-modules/wpScriptModules.php  |  2 +-
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 2c8c5683a1097..ef22363c7b504 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -544,16 +544,20 @@ private function get_import_map(): array {
 
 		$classic_script_dependencies = array();
 		if ( $wp_scripts instanceof WP_Scripts ) {
-			foreach ( $wp_scripts->registered as $dependency ) {
-				$handle = $dependency->handle;
+			$handles = array_merge(
+				$wp_scripts->queue,
+				$wp_scripts->to_do,
+				$wp_scripts->done
+			);
 
-				if (
-					! $wp_scripts->query( $handle, 'done' ) &&
-					! $wp_scripts->query( $handle, 'to_do' ) &&
-					! $wp_scripts->query( $handle, 'enqueued' )
-				) {
+			$processed = array();
+			while ( ! empty( $handles ) ) {
+				$handle = array_shift( $handles );
+
+				if ( isset( $processed[ $handle ] ) || ! isset( $wp_scripts->registered[ $handle ] ) ) {
 					continue;
 				}
+				$processed[ $handle ] = true;
 
 				$module_dependencies = $wp_scripts->get_data( $handle, 'module_dependencies' );
 				if ( is_array( $module_dependencies ) ) {
@@ -561,13 +565,19 @@ private function get_import_map(): array {
 						$classic_script_dependencies[] = $id;
 					}
 				}
+
+				foreach ( $wp_scripts->registered[ $handle ]->deps as $dep ) {
+					if ( ! isset( $processed[ $dep ] ) ) {
+						$handles[] = $dep;
+					}
+				}
 			}
 		}
 
 		$ids = array_unique(
 			array_merge(
 				$classic_script_dependencies,
-				array_keys( $this->get_dependencies( array_merge( $classic_script_dependencies, $this->queue ) ) )
+				array_keys( $this->get_dependencies( array_merge( $this->queue, $classic_script_dependencies ) ) )
 			)
 		);
 		foreach ( $ids as $id ) {
diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index 85c564c603e55..98a6bf02ba0ec 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -2113,11 +2113,11 @@ public function test_included_modules_concat_with_enqueued_dependencies() {
 		$this->assertCount( 0, $this->get_preloaded_script_modules(), 'Final module preload count was wrong.' );
 
 		$import_map = $this->get_import_map();
-		$this->assertCount( 4, $import_map, 'Final import map count was wrong.' );
 		$this->assertArrayHasKey( 'dependency-of-enqueued', $import_map, 'Final missing "dependency-of-enqueued" script module in import map.' );
 		$this->assertArrayHasKey( 'classic-transitive-dependency', $import_map, 'Final missing "classic-transitive-dependency" script module in import map.' );
 		$this->assertArrayHasKey( 'not-enqueued', $import_map, 'Final missing "not-enqueued" script module in import map.' );
 		$this->assertArrayHasKey( 'dependency-of-not-enqueued', $import_map, 'Final missing "dependency-of-not-enqueued" script module in import map.' );
+		$this->assertCount( 4, $import_map, 'Final import map count was wrong: ' . print_r( $import_map, true ) );
 	}
 
 	/**

From 6b56f5fccc0b39d5411c9cf0b2511b0ba6575c02 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Thu, 29 Jan 2026 18:34:50 -0800
Subject: [PATCH 24/42] Improve variable naming, add comment, and add phpdoc

---
 src/wp-includes/class-wp-script-modules.php | 14 +++++++++-----
 src/wp-includes/functions.wp-scripts.php    |  2 ++
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index ef22363c7b504..5e9c0929fab88 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -533,6 +533,9 @@ public function print_import_map() {
 	 * Returns the import map array.
 	 *
 	 * @since 6.5.0
+	 * @since 7.0.0 Script module dependencies ('module_dependencies') of classic scripts are now included.
+	 *
+	 * @global WP_Scripts $wp_scripts
 	 *
 	 * @return array<string, array<string, string>> Array with an `imports` key mapping to an array of script module
 	 *                                              identifiers and their respective URLs, including the version query.
@@ -542,7 +545,8 @@ private function get_import_map(): array {
 
 		$imports = array();
 
-		$classic_script_dependencies = array();
+		// Identify script modules that are dependencies of classic scripts.
+		$classic_script_module_dependencies = array();
 		if ( $wp_scripts instanceof WP_Scripts ) {
 			$handles = array_merge(
 				$wp_scripts->queue,
@@ -553,7 +557,6 @@ private function get_import_map(): array {
 			$processed = array();
 			while ( ! empty( $handles ) ) {
 				$handle = array_shift( $handles );
-
 				if ( isset( $processed[ $handle ] ) || ! isset( $wp_scripts->registered[ $handle ] ) ) {
 					continue;
 				}
@@ -562,7 +565,7 @@ private function get_import_map(): array {
 				$module_dependencies = $wp_scripts->get_data( $handle, 'module_dependencies' );
 				if ( is_array( $module_dependencies ) ) {
 					foreach ( $module_dependencies as $id ) {
-						$classic_script_dependencies[] = $id;
+						$classic_script_module_dependencies[] = $id;
 					}
 				}
 
@@ -574,10 +577,11 @@ private function get_import_map(): array {
 			}
 		}
 
+		// Note: the script modules in $this->queue are not included in the importmap because they get printed as scripts.
 		$ids = array_unique(
 			array_merge(
-				$classic_script_dependencies,
-				array_keys( $this->get_dependencies( array_merge( $this->queue, $classic_script_dependencies ) ) )
+				$classic_script_module_dependencies,
+				array_keys( $this->get_dependencies( array_merge( $this->queue, $classic_script_module_dependencies ) ) )
 			)
 		);
 		foreach ( $ids as $id ) {
diff --git a/src/wp-includes/functions.wp-scripts.php b/src/wp-includes/functions.wp-scripts.php
index c4a95dbbe390c..b31e78b1ffbb4 100644
--- a/src/wp-includes/functions.wp-scripts.php
+++ b/src/wp-includes/functions.wp-scripts.php
@@ -159,6 +159,7 @@ function wp_add_inline_script( $handle, $data, $position = 'after' ) {
  * @since 4.3.0 A return value was added.
  * @since 6.3.0 The $in_footer parameter of type boolean was overloaded to be an $args parameter of type array.
  * @since 6.9.0 The $fetchpriority parameter of type string was added to the $args parameter of type array.
+ * @since 7.0.0 The $module_dependencies parameter of type string[] was added to the $args parameter of type array.
  *
  * @param string                                   $handle Name of the script. Should be unique.
  * @param string|false                             $src    Full URL of the script, or path of the script relative to the WordPress root directory.
@@ -349,6 +350,7 @@ function wp_deregister_script( $handle ) {
  * @since 2.1.0
  * @since 6.3.0 The $in_footer parameter of type boolean was overloaded to be an $args parameter of type array.
  * @since 6.9.0 The $fetchpriority parameter of type string was added to the $args parameter of type array.
+ * @since 7.0.0 The $module_dependencies parameter of type string[] was added to the $args parameter of type array.
  *
  * @param string                                   $handle Name of the script. Should be unique.
  * @param string                                   $src    Full URL of the script, or path of the script relative to the WordPress root directory.

From cf8f813b598585bacdc927ab0f2bc8742292bf49 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Thu, 29 Jan 2026 18:38:46 -0800
Subject: [PATCH 25/42] Restore WP_Script_Modules::get_src() only returning
 string

---
 src/wp-includes/class-wp-script-modules.php | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 5e9c0929fab88..4de27ec079cdd 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -586,7 +586,7 @@ private function get_import_map(): array {
 		);
 		foreach ( $ids as $id ) {
 			$src = $this->get_src( $id );
-			if ( '' !== $src && null !== $src ) {
+			if ( '' !== $src ) {
 				$imports[ $id ] = $src;
 			}
 		}
@@ -822,11 +822,11 @@ private function sort_item_dependencies( string $id, array $import_types, array
 	 * @since 6.5.0
 	 *
 	 * @param string $id The script module identifier.
-	 * @return string|null The script module src with a version if relevant.
+	 * @return string The script module src with a version if relevant.
 	 */
-	private function get_src( string $id ): ?string {
+	private function get_src( string $id ): string {
 		if ( ! isset( $this->registered[ $id ] ) ) {
-			return null;
+			return '';
 		}
 
 		$script_module = $this->registered[ $id ];

From 34867dff496480b09ceb1c77051b38560edd144e Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Thu, 29 Jan 2026 20:58:06 -0800
Subject: [PATCH 26/42] Warn when script is enqueued with missing script module
 dependency

---
 src/wp-includes/class-wp-script-modules.php   | 22 +++++++++-
 .../tests/script-modules/wpScriptModules.php  | 42 +++++++++++++++++++
 2 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 4de27ec079cdd..51fb8acc13dcf 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -564,8 +564,27 @@ private function get_import_map(): array {
 
 				$module_dependencies = $wp_scripts->get_data( $handle, 'module_dependencies' );
 				if ( is_array( $module_dependencies ) ) {
+					$missing_module_dependencies = array();
 					foreach ( $module_dependencies as $id ) {
-						$classic_script_module_dependencies[] = $id;
+						if ( ! isset( $this->registered[ $id ] ) ) {
+							$missing_module_dependencies[] = $id;
+						} else {
+							$classic_script_module_dependencies[] = $id;
+						}
+					}
+
+					if ( count( $missing_module_dependencies ) > 0 ) {
+						_doing_it_wrong(
+							WP_Scripts::class . '::add',
+							sprintf(
+								/* translators: 1: Script handle, 2: 'module_dependencies', 3: List of missing dependency IDs. */
+								__( 'The script handle "%1$s" was enqueued with script module dependencies ("%2$s") that are not registered: %3$s.' ),
+								$handle,
+								'module_dependencies',
+								implode( wp_get_list_item_separator(), $missing_module_dependencies )
+							),
+							'7.0.0'
+						);
 					}
 				}
 
@@ -590,7 +609,6 @@ private function get_import_map(): array {
 				$imports[ $id ] = $src;
 			}
 		}
-
 		return array( 'imports' => $imports );
 	}
 
diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index 98a6bf02ba0ec..4756c6702b6d5 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -2120,6 +2120,48 @@ public function test_included_modules_concat_with_enqueued_dependencies() {
 		$this->assertCount( 4, $import_map, 'Final import map count was wrong: ' . print_r( $import_map, true ) );
 	}
 
+
+	/**
+	 * Tests that WP_Scripts emits a _doing_it_wrong() notice for missing script module dependencies.
+	 *
+	 * @ticket 61500
+	 * @ticket 64229
+	 * @covers WP_Script_Modules::get_import_map
+	 */
+	public function test_wp_scripts_doing_it_wrong_for_missing_script_module_dependencies() {
+		$expected_incorrect_usage = 'WP_Scripts::add';
+		$this->setExpectedIncorrectUsage( $expected_incorrect_usage );
+
+		wp_enqueue_script(
+			'registered-dep',
+			'/registered-dep.js',
+			array(),
+			null,
+			array(
+				'module_dependencies' => array( 'does-not-exist' ),
+			)
+		);
+
+		$import_map = $this->get_import_map();
+		$this->assertSame( array(), $import_map, 'Expected importmap to be empty.' );
+		$markup = get_echo( 'wp_print_scripts' );
+
+		// TODO: Should this actually be omitted?
+		$this->assertStringContainsString( 'registered-dep.js', $markup, 'Expected script to be present.' );
+
+		$this->assertArrayHasKey(
+			$expected_incorrect_usage,
+			$this->caught_doing_it_wrong,
+			"Expected $expected_incorrect_usage to trigger a _doing_it_wrong() notice for missing dependency."
+		);
+
+		$this->assertStringContainsString(
+			'The script handle "registered-dep" was enqueued with script module dependencies ("module_dependencies") that are not registered: does-not-exist',
+			$this->caught_doing_it_wrong[ $expected_incorrect_usage ],
+			'Expected _doing_it_wrong() notice to indicate missing script module dependencies for enqueued script.'
+		);
+	}
+
 	/**
 	 * Tests various ways of printing and dependency ordering of script modules.
 	 *

From babe954820fdd7b7617057722702770a56841c10 Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@gmail.com>
Date: Fri, 30 Jan 2026 13:44:54 -0800
Subject: [PATCH 27/42] Use array_pop() instead of array_shift() to avoid
 re-indexing

Co-authored-by: Jon Surrell <sirreal@users.noreply.github.com>
---
 src/wp-includes/class-wp-script-modules.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index 51fb8acc13dcf..bed609c67fa60 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -556,7 +556,7 @@ private function get_import_map(): array {
 
 			$processed = array();
 			while ( ! empty( $handles ) ) {
-				$handle = array_shift( $handles );
+				$handle = array_pop( $handles );
 				if ( isset( $processed[ $handle ] ) || ! isset( $wp_scripts->registered[ $handle ] ) ) {
 					continue;
 				}

From b45082629c3a054af3bfa50367fe11a61ae63741 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 14:10:57 -0800
Subject: [PATCH 28/42] Validate module_dependencies in WP_Scripts::add_data()

Ensures that the 'module_dependencies' value is an array of strings. Non-array values trigger a _doing_it_wrong() notice and return false, while non-string items within an array are stripped with a notice.

Co-authored-by: Jon Surrell <jonsurrell@git.wordpress.org>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
---
 src/wp-includes/class-wp-scripts.php         | 39 +++++++++++++++
 tests/phpunit/tests/dependencies/scripts.php | 52 ++++++++++++++++++++
 2 files changed, 91 insertions(+)

diff --git a/src/wp-includes/class-wp-scripts.php b/src/wp-includes/class-wp-scripts.php
index 0ed7087a93f4c..fcc4fe0e5a04c 100644
--- a/src/wp-includes/class-wp-scripts.php
+++ b/src/wp-includes/class-wp-scripts.php
@@ -920,6 +920,45 @@ public function add_data( $handle, $key, $value ) {
 				);
 				return false;
 			}
+		} elseif ( 'module_dependencies' === $key ) {
+			if ( ! is_array( $value ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					sprintf(
+						/* translators: 1: 'module_dependencies', 2: Script handle. */
+						__( 'The value for "%1$s" must be an array for the "%2$s" script.' ),
+						'module_dependencies',
+						$handle
+					),
+					'7.0.0'
+				);
+				return false;
+			}
+
+			$sanitized_value = array();
+			$has_invalid_ids = false;
+			foreach ( $value as $id ) {
+				if ( ! is_string( $id ) ) {
+					$has_invalid_ids = true;
+				} else {
+					$sanitized_value[] = $id;
+				}
+			}
+
+			if ( $has_invalid_ids ) {
+				_doing_it_wrong(
+					__METHOD__,
+					sprintf(
+						/* translators: 1: Script handle, 2: 'module_dependencies' */
+						__( 'The script handle "%1$s" has one or more of its script module dependencies ("%2$s") which are not strings.' ),
+						$handle,
+						'module_dependencies'
+					),
+					'7.0.0'
+				);
+			}
+
+			$value = $sanitized_value;
 		}
 		return parent::add_data( $handle, $key, $value );
 	}
diff --git a/tests/phpunit/tests/dependencies/scripts.php b/tests/phpunit/tests/dependencies/scripts.php
index 846cbb125d26c..fffb3599f0bea 100644
--- a/tests/phpunit/tests/dependencies/scripts.php
+++ b/tests/phpunit/tests/dependencies/scripts.php
@@ -1277,6 +1277,58 @@ public function test_invalid_fetchpriority_on_alias() {
 		$this->assertArrayNotHasKey( 'fetchpriority', wp_scripts()->registered['alias']->extra );
 	}
 
+	/**
+	 * Tests validation of module_dependencies in WP_Scripts::add_data().
+	 *
+	 * @ticket 61500
+	 *
+	 * @covers WP_Scripts::add_data
+	 *
+	 * @dataProvider data_add_data_module_dependencies_validation
+	 *
+	 * @param mixed      $data     Data to add.
+	 * @param string     $message  Expected error message.
+	 * @param bool       $expected Expected return value.
+	 * @param array|null $stored   Expected stored value.
+	 */
+	public function test_add_data_module_dependencies_validation( $data, string $message, bool $expected, ?array $stored ) {
+		wp_register_script( 'test-script', '/test.js' );
+
+		$expected_incorrect_usage = 'WP_Scripts::add_data';
+		$this->setExpectedIncorrectUsage( $expected_incorrect_usage );
+
+		$this->assertSame( $expected, wp_scripts()->add_data( 'test-script', 'module_dependencies', $data ) );
+		$this->assertStringContainsString( $message, $this->caught_doing_it_wrong[ $expected_incorrect_usage ] );
+
+		if ( null === $stored ) {
+			$this->assertFalse( wp_scripts()->get_data( 'test-script', 'module_dependencies' ) );
+		} else {
+			$this->assertSame( $stored, wp_scripts()->get_data( 'test-script', 'module_dependencies' ) );
+		}
+	}
+
+	/**
+	 * Data provider.
+	 *
+	 * @return array<string, array{data: mixed, message: string, expected: bool, stored: string[]|null}>
+	 */
+	public function data_add_data_module_dependencies_validation(): array {
+		return array(
+			'non-array' => array(
+				'data'     => 'not-an-array',
+				'message'  => 'The value for "module_dependencies" must be an array',
+				'expected' => false,
+				'stored'   => null,
+			),
+			'bad-items' => array(
+				'data'     => array( 'valid', 123, true, array() ),
+				'message'  => 'has script module dependencies ("module_dependencies") that are not strings and have been removed',
+				'expected' => true,
+				'stored'   => array( 'valid' ),
+			),
+		);
+	}
+
 	/**
 	 * Data provider.
 	 *

From 269c4c74b28df3e235000e86ecb7a0534453a8cc Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 14:34:35 -0800
Subject: [PATCH 29/42] Validate extra args in wp_register_script() and
 wp_enqueue_script()

Introduces _wp_scripts_check_extra_args() to check for unrecognized keys in the $args parameter of script registration and enqueueing functions, triggering a _doing_it_wrong() notice if found. This helps prevent typos and usage of unsupported arguments.

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
---
 src/wp-includes/functions.wp-scripts.php     | 29 ++++++++
 tests/phpunit/tests/dependencies/scripts.php | 69 +++++++++++++++++++-
 2 files changed, 97 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/functions.wp-scripts.php b/src/wp-includes/functions.wp-scripts.php
index b31e78b1ffbb4..cdd2c6b7a86a5 100644
--- a/src/wp-includes/functions.wp-scripts.php
+++ b/src/wp-includes/functions.wp-scripts.php
@@ -68,6 +68,33 @@ function _wp_scripts_maybe_doing_it_wrong( $function_name, $handle = '' ) {
 	);
 }
 
+/**
+ * Checks if the $args array contains any unrecognized keys.
+ *
+ * @ignore
+ * @since 7.0.0
+ *
+ * @param string $function_name Function name.
+ * @param array  $args          Array of extra args for the script.
+ */
+function _wp_scripts_check_extra_args( string $function_name, array $args ) {
+	$allowed_keys = array( 'strategy', 'in_footer', 'fetchpriority', 'module_dependencies' );
+	$unknown_keys = array_diff( array_keys( $args ), $allowed_keys );
+
+	if ( ! empty( $unknown_keys ) ) {
+		_doing_it_wrong(
+			$function_name,
+			sprintf(
+				/* translators: 1: $args, 2: List of unrecognized keys. */
+				__( 'Unrecognized keys in the %1$s array: %2$s.' ),
+				'$args',
+				implode( wp_get_list_item_separator(), $unknown_keys )
+			),
+			'7.0.0'
+		);
+	}
+}
+
 /**
  * Prints scripts in document head that are in the $handles queue.
  *
@@ -187,6 +214,7 @@ function wp_register_script( $handle, $src, $deps = array(), $ver = false, $args
 		);
 	}
 	_wp_scripts_maybe_doing_it_wrong( __FUNCTION__, $handle );
+	_wp_scripts_check_extra_args( __FUNCTION__, $args );
 
 	$wp_scripts = wp_scripts();
 
@@ -382,6 +410,7 @@ function wp_enqueue_script( $handle, $src = '', $deps = array(), $ver = false, $
 				'in_footer' => (bool) $args,
 			);
 		}
+		_wp_scripts_check_extra_args( __FUNCTION__, $args );
 
 		if ( $src ) {
 			$wp_scripts->add( $_handle[0], $src, $deps, $ver );
diff --git a/tests/phpunit/tests/dependencies/scripts.php b/tests/phpunit/tests/dependencies/scripts.php
index fffb3599f0bea..ce60b5c0cdf3e 100644
--- a/tests/phpunit/tests/dependencies/scripts.php
+++ b/tests/phpunit/tests/dependencies/scripts.php
@@ -105,6 +105,73 @@ public function get_script_html() {
 		$this->assertEqualHTML( $expected, $processor->get_script_html(), '<body>', $message );
 	}
 
+	/**
+	 * Tests that scripts trigger _doing_it_wrong for unrecognized keys in the $args array.
+	 *
+	 * @ticket 63486
+	 *
+	 * @covers ::wp_register_script
+	 * @covers ::wp_enqueue_script
+	 * @covers ::_wp_scripts_check_extra_args
+	 *
+	 * @dataProvider data_unrecognized_keys_in_args
+	 *
+	 * @param string $function_name Function name to call.
+	 * @param array  $args          Arguments to pass to the function.
+	 * @param string $expected_msg  Expected error message substring.
+	 */
+	public function test_unrecognized_keys_in_args( string $function_name, array $args, string $expected_msg ) {
+		$this->setExpectedIncorrectUsage( $function_name );
+
+		call_user_func_array( $function_name, $args );
+
+		$this->assertStringContainsString(
+			$expected_msg,
+			$this->caught_doing_it_wrong[ $function_name ]
+		);
+	}
+
+	/**
+	 * Data provider for test_unrecognized_keys_in_args.
+	 *
+	 * @return array<string, array{function_name: string, args: array, expected_msg: string}>
+	 */
+	public function data_unrecognized_keys_in_args(): array {
+		return array(
+			'register_script' => array(
+				'function_name' => 'wp_register_script',
+				'args'          => array(
+					'unrecognized-key-register',
+					'/script.js',
+					array(),
+					null,
+					array(
+						'unrecognized_key' => 'value',
+						'another_bad_key'  => 'value',
+					),
+				),
+				'expected_msg'  => 'Unrecognized keys in the $args array: unrecognized_key, another_bad_key',
+			),
+			'enqueue_script'  => array(
+				'function_name' => 'wp_enqueue_script',
+				'args'          => array(
+					'unrecognized-key-enqueue',
+					'/script.js',
+					array(),
+					null,
+					array(
+						'strategy'            => 'defer',
+						'in_footer'           => true,
+						'fetchpriority'       => 'high',
+						'module_dependencies' => array( 'foo' ),
+						'invalid_key'         => 'bar',
+					),
+				),
+				'expected_msg'  => 'Unrecognized keys in the $args array: invalid_key',
+			),
+		);
+	}
+
 	/**
 	 * Test versioning
 	 *
@@ -1322,7 +1389,7 @@ public function data_add_data_module_dependencies_validation(): array {
 			),
 			'bad-items' => array(
 				'data'     => array( 'valid', 123, true, array() ),
-				'message'  => 'has script module dependencies ("module_dependencies") that are not strings and have been removed',
+				'message'  => 'has one or more of its script module dependencies ("module_dependencies") which are not strings',
 				'expected' => true,
 				'stored'   => array( 'valid' ),
 			),

From 3c2c84b26bdd2e6cbcec8b6dd4036fbe87e31954 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 14:46:35 -0800
Subject: [PATCH 30/42] Refactor wp_register_script() and wp_enqueue_script()
 to avoid code duplication

Introduces _wp_scripts_add_args_data() to consolidate the logic for validating unrecognized keys in the $args parameter and adding the corresponding data to the script. This removes redundant code blocks and ensures consistent validation and processing across both functions.

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
---
 src/wp-includes/functions.wp-scripts.php     | 52 +++++++++-----------
 tests/phpunit/tests/dependencies/scripts.php |  2 +-
 2 files changed, 23 insertions(+), 31 deletions(-)

diff --git a/src/wp-includes/functions.wp-scripts.php b/src/wp-includes/functions.wp-scripts.php
index cdd2c6b7a86a5..b4ce49ac0763e 100644
--- a/src/wp-includes/functions.wp-scripts.php
+++ b/src/wp-includes/functions.wp-scripts.php
@@ -69,15 +69,17 @@ function _wp_scripts_maybe_doing_it_wrong( $function_name, $handle = '' ) {
 }
 
 /**
- * Checks if the $args array contains any unrecognized keys.
+ * Adds the data for the recognized args and warns for unrecognized args.
  *
  * @ignore
  * @since 7.0.0
  *
- * @param string $function_name Function name.
- * @param array  $args          Array of extra args for the script.
+ * @param string     $function_name Function name.
+ * @param WP_Scripts $wp_scripts    WP_Scripts instance.
+ * @param string     $handle        Script handle.
+ * @param array      $args          Array of extra args for the script.
  */
-function _wp_scripts_check_extra_args( string $function_name, array $args ) {
+function _wp_scripts_add_args_data( string $function_name, WP_Scripts $wp_scripts, string $handle, array $args ) {
 	$allowed_keys = array( 'strategy', 'in_footer', 'fetchpriority', 'module_dependencies' );
 	$unknown_keys = array_diff( array_keys( $args ), $allowed_keys );
 
@@ -93,6 +95,19 @@ function _wp_scripts_check_extra_args( string $function_name, array $args ) {
 			'7.0.0'
 		);
 	}
+
+	if ( ! empty( $args['in_footer'] ) ) {
+		$wp_scripts->add_data( $handle, 'group', 1 );
+	}
+	if ( ! empty( $args['strategy'] ) ) {
+		$wp_scripts->add_data( $handle, 'strategy', $args['strategy'] );
+	}
+	if ( ! empty( $args['fetchpriority'] ) ) {
+		$wp_scripts->add_data( $handle, 'fetchpriority', $args['fetchpriority'] );
+	}
+	if ( ! empty( $args['module_dependencies'] ) ) {
+		$wp_scripts->add_data( $handle, 'module_dependencies', $args['module_dependencies'] );
+	}
 }
 
 /**
@@ -214,23 +229,12 @@ function wp_register_script( $handle, $src, $deps = array(), $ver = false, $args
 		);
 	}
 	_wp_scripts_maybe_doing_it_wrong( __FUNCTION__, $handle );
-	_wp_scripts_check_extra_args( __FUNCTION__, $args );
 
 	$wp_scripts = wp_scripts();
 
 	$registered = $wp_scripts->add( $handle, $src, $deps, $ver );
-	if ( ! empty( $args['in_footer'] ) ) {
-		$wp_scripts->add_data( $handle, 'group', 1 );
-	}
-	if ( ! empty( $args['strategy'] ) ) {
-		$wp_scripts->add_data( $handle, 'strategy', $args['strategy'] );
-	}
-	if ( ! empty( $args['fetchpriority'] ) ) {
-		$wp_scripts->add_data( $handle, 'fetchpriority', $args['fetchpriority'] );
-	}
-	if ( ! empty( $args['module_dependencies'] ) ) {
-		$wp_scripts->add_data( $handle, 'module_dependencies', $args['module_dependencies'] );
-	}
+	_wp_scripts_add_args_data( __FUNCTION__, $wp_scripts, $handle, $args );
+
 	return $registered;
 }
 
@@ -410,23 +414,11 @@ function wp_enqueue_script( $handle, $src = '', $deps = array(), $ver = false, $
 				'in_footer' => (bool) $args,
 			);
 		}
-		_wp_scripts_check_extra_args( __FUNCTION__, $args );
 
 		if ( $src ) {
 			$wp_scripts->add( $_handle[0], $src, $deps, $ver );
 		}
-		if ( ! empty( $args['in_footer'] ) ) {
-			$wp_scripts->add_data( $_handle[0], 'group', 1 );
-		}
-		if ( ! empty( $args['strategy'] ) ) {
-			$wp_scripts->add_data( $_handle[0], 'strategy', $args['strategy'] );
-		}
-		if ( ! empty( $args['fetchpriority'] ) ) {
-			$wp_scripts->add_data( $_handle[0], 'fetchpriority', $args['fetchpriority'] );
-		}
-		if ( ! empty( $args['module_dependencies'] ) ) {
-			$wp_scripts->add_data( $_handle[0], 'module_dependencies', $args['module_dependencies'] );
-		}
+		_wp_scripts_add_args_data( __FUNCTION__, $wp_scripts, $_handle[0], $args );
 	}
 
 	$wp_scripts->enqueue( $handle );
diff --git a/tests/phpunit/tests/dependencies/scripts.php b/tests/phpunit/tests/dependencies/scripts.php
index ce60b5c0cdf3e..f979e2320396c 100644
--- a/tests/phpunit/tests/dependencies/scripts.php
+++ b/tests/phpunit/tests/dependencies/scripts.php
@@ -112,7 +112,7 @@ public function get_script_html() {
 	 *
 	 * @covers ::wp_register_script
 	 * @covers ::wp_enqueue_script
-	 * @covers ::_wp_scripts_check_extra_args
+	 * @covers ::_wp_scripts_add_args_data
 	 *
 	 * @dataProvider data_unrecognized_keys_in_args
 	 *

From 354f42de50c629d5ebf105f5fb6014ceecfab836 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 14:52:59 -0800
Subject: [PATCH 31/42] Standardize wp_scripts global handling in script module
 tests

Updates Tests_Script_Modules_WpScriptModules to use the same setup/teardown pattern for the $wp_scripts global as Tests_Dependencies_Scripts, ensuring it is properly backed up and restored for each test case.

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
---
 .../tests/script-modules/wpScriptModules.php  | 44 +++++--------------
 1 file changed, 12 insertions(+), 32 deletions(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index 4756c6702b6d5..2accd43d588a7 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -21,6 +21,11 @@ class Tests_Script_Modules_WpScriptModules extends WP_UnitTestCase {
 	 */
 	protected $original_wp_version;
 
+	/**
+	 * @var WP_Scripts|null
+	 */
+	protected $old_wp_scripts;
+
 	/**
 	 * Instance of WP_Script_Modules.
 	 *
@@ -36,9 +41,12 @@ public function set_up() {
 		parent::set_up();
 		$this->original_script_modules = $wp_script_modules;
 		$this->original_wp_version     = $wp_version;
+		$this->old_wp_scripts          = $GLOBALS['wp_scripts'] ?? null;
 		$wp_script_modules             = null;
 		$this->script_modules          = wp_script_modules();
-		unset( $GLOBALS['wp_scripts'] );
+
+		$GLOBALS['wp_scripts']                  = new WP_Scripts();
+		$GLOBALS['wp_scripts']->default_version = get_bloginfo( 'version' );
 	}
 
 	/**
@@ -46,40 +54,12 @@ public function set_up() {
 	 */
 	public function tear_down() {
 		global $wp_script_modules, $wp_version;
+		$wp_script_modules      = $this->original_script_modules;
+		$wp_version             = $this->original_wp_version;
+		$GLOBALS['wp_scripts']  = $this->old_wp_scripts;
 		parent::tear_down();
-		$wp_script_modules = $this->original_script_modules;
-		$wp_version        = $this->original_wp_version;
-	}
-
-	private static $wp_scripts;
-	private static $wp_scripts_was_set = false;
-
-	public static function set_up_before_class() {
-		parent::set_up_before_class();
-
-		// If the global is set, store it for restoring when done testing.
-		static::$wp_scripts_was_set = array_key_exists( 'wp_scripts', $GLOBALS );
-		if ( static::$wp_scripts_was_set ) {
-			static::$wp_scripts = $GLOBALS['wp_scripts'];
-			unset( $GLOBALS['wp_scripts'] );
-		}
-	}
-
-	public static function tear_down_after_class() {
-		// Restore the global if it was set before running this set of tests.
-		if ( static::$wp_scripts_was_set ) {
-			$GLOBALS['wp_scripts'] = static::$wp_scripts;
-		}
-
-		parent::tear_down_after_class();
-	}
-
-	public function clean_up_global_scope() {
-		unset( $GLOBALS['wp_scripts'] );
-		parent::clean_up_global_scope();
 	}
 
-
 	/**
 	 * Gets a list of the enqueued script modules.
 	 *

From ae642f4fadc5e05bb2912af4faaf0808ec040f65 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 14:54:21 -0800
Subject: [PATCH 32/42] Use PHP 7.4 class member types

---
 .../tests/script-modules/wpScriptModules.php  | 22 ++++---------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index 2accd43d588a7..cc6bced9d1c61 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -11,27 +11,13 @@
  */
 class Tests_Script_Modules_WpScriptModules extends WP_UnitTestCase {
 
-	/**
-	 * @var WP_Script_Modules
-	 */
-	protected $original_script_modules;
+	protected WP_Script_Modules $original_script_modules;
 
-	/**
-	 * @var string
-	 */
-	protected $original_wp_version;
+	protected string $original_wp_version;
 
-	/**
-	 * @var WP_Scripts|null
-	 */
-	protected $old_wp_scripts;
+	protected ?WP_Scripts $old_wp_scripts;
 
-	/**
-	 * Instance of WP_Script_Modules.
-	 *
-	 * @var WP_Script_Modules
-	 */
-	protected $script_modules;
+	protected WP_Script_Modules $script_modules;
 
 	/**
 	 * Set up.

From 8a782ac66f0bc5af169017a145a12714749b7d76 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 14:55:25 -0800
Subject: [PATCH 33/42] Fix variable alignment

---
 tests/phpunit/tests/script-modules/wpScriptModules.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index cc6bced9d1c61..af33262b9989d 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -40,9 +40,9 @@ public function set_up() {
 	 */
 	public function tear_down() {
 		global $wp_script_modules, $wp_version;
-		$wp_script_modules      = $this->original_script_modules;
-		$wp_version             = $this->original_wp_version;
-		$GLOBALS['wp_scripts']  = $this->old_wp_scripts;
+		$wp_script_modules     = $this->original_script_modules;
+		$wp_version            = $this->original_wp_version;
+		$GLOBALS['wp_scripts'] = $this->old_wp_scripts;
 		parent::tear_down();
 	}
 

From 6a3141a81298a745fe014d749460769f235c8558 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 15:00:03 -0800
Subject: [PATCH 34/42] Use globals consistently

---
 .../tests/script-modules/wpScriptModules.php       | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index af33262b9989d..70d85727afe6d 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -23,7 +23,7 @@ class Tests_Script_Modules_WpScriptModules extends WP_UnitTestCase {
 	 * Set up.
 	 */
 	public function set_up() {
-		global $wp_script_modules, $wp_version;
+		global $wp_script_modules, $wp_scripts, $wp_version;
 		parent::set_up();
 		$this->original_script_modules = $wp_script_modules;
 		$this->original_wp_version     = $wp_version;
@@ -31,18 +31,18 @@ public function set_up() {
 		$wp_script_modules             = null;
 		$this->script_modules          = wp_script_modules();
 
-		$GLOBALS['wp_scripts']                  = new WP_Scripts();
-		$GLOBALS['wp_scripts']->default_version = get_bloginfo( 'version' );
+		$wp_scripts                  = new WP_Scripts();
+		$wp_scripts->default_version = get_bloginfo( 'version' );
 	}
 
 	/**
 	 * Tear down.
 	 */
 	public function tear_down() {
-		global $wp_script_modules, $wp_version;
-		$wp_script_modules     = $this->original_script_modules;
-		$wp_version            = $this->original_wp_version;
-		$GLOBALS['wp_scripts'] = $this->old_wp_scripts;
+		global $wp_script_modules, $wp_scripts, $wp_version;
+		$wp_script_modules = $this->original_script_modules;
+		$wp_version        = $this->original_wp_version;
+		$wp_scripts        = $this->old_wp_scripts;
 		parent::tear_down();
 	}
 

From 07ab8d61b5326e6c9ee8110e9a6fc49e15d5e827 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 15:04:13 -0800
Subject: [PATCH 35/42] Add descriptions to script module dependency tests

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
---
 tests/phpunit/tests/script-modules/wpScriptModules.php | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index 70d85727afe6d..41e746761e492 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -1982,7 +1982,11 @@ public static function data_invalid_script_module_data(): array {
 	}
 
 	/**
+	 * Tests that script modules identified as dependencies of classic scripts are included in the import map.
+	 *
 	 * @ticket 61500
+	 *
+	 * @covers WP_Script_Modules::get_import_map
 	 */
 	public function test_included_module_appears_in_importmap() {
 		$this->script_modules->register( 'dependency', '/dep.js' );
@@ -2014,7 +2018,12 @@ public function test_included_module_appears_in_importmap() {
 	}
 
 	/**
+	 * Tests that script modules identified as dependencies of classic scripts are correctly included in the import map,
+	 * even when those module dependencies are attached to transitive classic script dependencies.
+	 *
 	 * @ticket 61500
+	 *
+	 * @covers WP_Script_Modules::get_import_map
 	 */
 	public function test_included_modules_concat_with_enqueued_dependencies() {
 		$this->script_modules->register( 'dependency-of-enqueued', '/dependency-of-enqueued.js' );
@@ -2086,7 +2095,6 @@ public function test_included_modules_concat_with_enqueued_dependencies() {
 		$this->assertCount( 4, $import_map, 'Final import map count was wrong: ' . print_r( $import_map, true ) );
 	}
 
-
 	/**
 	 * Tests that WP_Scripts emits a _doing_it_wrong() notice for missing script module dependencies.
 	 *

From 907cb0d6a9f5eacee22bdb5e0a980f7a75b1f0c2 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 15:13:32 -0800
Subject: [PATCH 36/42] Refactor and simplify script module dependency tests

Splits the large test_included_modules_concat_with_enqueued_dependencies test into two focused test cases, uses standard handles, and simplifies assertions. This also removes the need for hacky internal property resets.

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
---
 .../tests/script-modules/wpScriptModules.php  | 81 +++++++++----------
 1 file changed, 40 insertions(+), 41 deletions(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index 41e746761e492..6034663517c43 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -2010,22 +2010,21 @@ public function test_included_module_appears_in_importmap() {
 
 		$this->assertSame( array(), $this->get_enqueued_script_modules(), 'Final enqueued script modules was wrong.' );
 		$this->assertSame( array(), $this->get_preloaded_script_modules(), 'Final module preloads was wrong.' );
-
-		$import_map = $this->get_import_map();
-		$this->assertCount( 2, $import_map, 'Final import map count was wrong.' );
-		$this->assertArrayHasKey( 'example', $import_map, 'Final missing "example" script module in import map.' );
-		$this->assertArrayHasKey( 'dependency', $import_map, 'Final missing "dependency" script module in import map.' );
+		$this->assertEqualSets(
+			array( 'example', 'dependency' ),
+			array_keys( $this->get_import_map() ),
+			'Import map keys were wrong.'
+		);
 	}
 
 	/**
-	 * Tests that script modules identified as dependencies of classic scripts are correctly included in the import map,
-	 * even when those module dependencies are attached to transitive classic script dependencies.
+	 * Tests that dynamic dependencies of enqueued script modules are included in the import map.
 	 *
 	 * @ticket 61500
 	 *
 	 * @covers WP_Script_Modules::get_import_map
 	 */
-	public function test_included_modules_concat_with_enqueued_dependencies() {
+	public function test_import_map_includes_dynamic_dependencies_of_enqueued_modules() {
 		$this->script_modules->register( 'dependency-of-enqueued', '/dependency-of-enqueued.js' );
 		$this->script_modules->enqueue(
 			'enqueued',
@@ -2038,32 +2037,32 @@ public function test_included_modules_concat_with_enqueued_dependencies() {
 			)
 		);
 
-		$this->script_modules->register( 'classic-transitive-dependency', '/classic-transitive-dependency.js' );
+		$enqueued = $this->get_enqueued_script_modules();
+		$this->assertCount( 1, $enqueued, 'Enqueue count was wrong.' );
+		$this->assertArrayHasKey( 'enqueued', $enqueued, 'Missing "enqueued" script module enqueue.' );
+		$this->assertCount( 0, $this->get_preloaded_script_modules(), 'Module preload count was wrong.' );
+		$this->assertEqualSets(
+			array( 'dependency-of-enqueued' ),
+			array_keys( $this->get_import_map() ),
+			'Import map keys were wrong.'
+		);
+	}
 
+	/**
+	 * Tests that script module dependencies of enqueued classic scripts (including transitive ones) are included in the import map.
+	 *
+	 * @ticket 61500
+	 *
+	 * @covers WP_Script_Modules::get_import_map
+	 */
+	public function test_import_map_includes_dependencies_of_classic_scripts_recursive() {
+		$this->script_modules->register( 'classic-transitive-dependency', '/classic-transitive-dependency.js' );
 		$this->script_modules->register( 'dependency-of-not-enqueued', '/dependency-of-not-enqueued.js' );
 		$this->script_modules->register( 'not-enqueued', '/not-enqueued.js', array( 'dependency-of-not-enqueued' ) );
 
-		// Only dependency-enqueued should be printed.
-		$enqueued = $this->get_enqueued_script_modules();
-		$this->assertCount( 1, $enqueued, 'Initial enqueue count was wrong.' );
-		$this->assertArrayHasKey( 'enqueued', $enqueued, 'Initial missing "enqueued" script module enqueue.' );
-		$this->assertCount( 0, $this->get_preloaded_script_modules(), 'Initial module preload count was wrong.' );
-
-		$import_map = $this->get_import_map();
-		$this->assertCount( 1, $import_map, 'Initial import map count was wrong.' );
-		$this->assertArrayHasKey( 'dependency-of-enqueued', $import_map, 'Initial missing "dependency-of-enqueued" script module in import map.' );
-
-		// Reset the printed modules so we can check again later.
-		$reflection    = new ReflectionClass( $this->script_modules );
-		$done_property = $reflection->getProperty( 'done' );
-		if ( PHP_VERSION_ID < 80100 ) {
-			$done_property->setAccessible( true );
-		}
-		$done_property->setValue( $this->script_modules, array() );
-
 		// Enqueuing a script with a module dependency should add it to the import map.
 		wp_register_script(
-			'_test_classic-dependency_',
+			'classic-transitive-dep',
 			'/classic-transitive-dep.js',
 			array(),
 			false,
@@ -2072,9 +2071,9 @@ public function test_included_modules_concat_with_enqueued_dependencies() {
 			)
 		);
 		wp_enqueue_script(
-			'_test_classic_',
+			'classic',
 			'/classic.js',
-			array( '_test_classic-dependency_' ),
+			array( 'classic-transitive-dep' ),
 			false,
 			array(
 				'module_dependencies' => array( 'not-enqueued' ),
@@ -2082,17 +2081,17 @@ public function test_included_modules_concat_with_enqueued_dependencies() {
 		);
 
 		$enqueued = $this->get_enqueued_script_modules();
-		$this->assertCount( 1, $enqueued, 'Final enqueue count was wrong.' );
-		$this->assertArrayHasKey( 'enqueued', $enqueued, 'Final missing "enqueued" script module enqueue.' );
-
-		$this->assertCount( 0, $this->get_preloaded_script_modules(), 'Final module preload count was wrong.' );
-
-		$import_map = $this->get_import_map();
-		$this->assertArrayHasKey( 'dependency-of-enqueued', $import_map, 'Final missing "dependency-of-enqueued" script module in import map.' );
-		$this->assertArrayHasKey( 'classic-transitive-dependency', $import_map, 'Final missing "classic-transitive-dependency" script module in import map.' );
-		$this->assertArrayHasKey( 'not-enqueued', $import_map, 'Final missing "not-enqueued" script module in import map.' );
-		$this->assertArrayHasKey( 'dependency-of-not-enqueued', $import_map, 'Final missing "dependency-of-not-enqueued" script module in import map.' );
-		$this->assertCount( 4, $import_map, 'Final import map count was wrong: ' . print_r( $import_map, true ) );
+		$this->assertCount( 0, $enqueued, 'Enqueue count was wrong.' );
+		$this->assertCount( 0, $this->get_preloaded_script_modules(), 'Module preload count was wrong.' );
+		$this->assertEqualSets(
+			array(
+				'classic-transitive-dependency',
+				'not-enqueued',
+				'dependency-of-not-enqueued',
+			),
+			array_keys( $this->get_import_map() ),
+			'Import map keys were wrong.'
+		);
 	}
 
 	/**

From 7f536427db89227a576963f084f5c4716a2e56da Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 15:34:58 -0800
Subject: [PATCH 37/42] Add comment explaining why a classic script with a
 missing dynamic script module dependency still prints

---
 .../phpunit/tests/script-modules/wpScriptModules.php | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index 6034663517c43..f820b4f30128f 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -2119,8 +2119,16 @@ public function test_wp_scripts_doing_it_wrong_for_missing_script_module_depende
 		$this->assertSame( array(), $import_map, 'Expected importmap to be empty.' );
 		$markup = get_echo( 'wp_print_scripts' );
 
-		// TODO: Should this actually be omitted?
-		$this->assertStringContainsString( 'registered-dep.js', $markup, 'Expected script to be present.' );
+		/*
+		 * In the future, we may want to have missing script module dependencies for classic scripts to cause the
+		 * classic script to not be printed. This would align the behavior with script modules that have missing
+		 * script module dependencies, and classic scripts that have missing classic script dependencies. Nevertheless,
+		 * since script module dependencies rely on dynamic imports, the dependency may not be as strong. This means
+		 * the classic script may still work or have a fallback in case the script module fails to dynamically import.
+		 * This same change could be made for script modules as well, where if a script module has a missing dynamic
+		 * script module dependency, this could similarly not because to omit printing the dependent script module.
+		 */
+		$this->assertStringContainsString( 'registered-dep.js', $markup, 'Expected script to be present, even though it has a missing script module dependency.' );
 
 		$this->assertArrayHasKey(
 			$expected_incorrect_usage,

From 7ddcdd704c6c8e89504ecd16d6a595dabcb4060c Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@gmail.com>
Date: Fri, 30 Jan 2026 16:36:16 -0800
Subject: [PATCH 38/42] Improve phrasing

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
---
 tests/phpunit/tests/script-modules/wpScriptModules.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index f820b4f30128f..8c3dd0af50876 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -2126,7 +2126,7 @@ public function test_wp_scripts_doing_it_wrong_for_missing_script_module_depende
 		 * since script module dependencies rely on dynamic imports, the dependency may not be as strong. This means
 		 * the classic script may still work or have a fallback in case the script module fails to dynamically import.
 		 * This same change could be made for script modules as well, where if a script module has a missing dynamic
-		 * script module dependency, this could similarly not because to omit printing the dependent script module.
+		 * script module dependency, this might similarly not be sufficient reason to omit printing the dependent script module.
 		 */
 		$this->assertStringContainsString( 'registered-dep.js', $markup, 'Expected script to be present, even though it has a missing script module dependency.' );
 

From 0cb95e0eb621db81e9a4fcef3751f1ccb39b62c0 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 16:34:54 -0800
Subject: [PATCH 39/42] Improve param default value description

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
---
 src/wp-includes/functions.wp-scripts.php | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/wp-includes/functions.wp-scripts.php b/src/wp-includes/functions.wp-scripts.php
index b4ce49ac0763e..a43ae8de28e90 100644
--- a/src/wp-includes/functions.wp-scripts.php
+++ b/src/wp-includes/functions.wp-scripts.php
@@ -82,7 +82,6 @@ function _wp_scripts_maybe_doing_it_wrong( $function_name, $handle = '' ) {
 function _wp_scripts_add_args_data( string $function_name, WP_Scripts $wp_scripts, string $handle, array $args ) {
 	$allowed_keys = array( 'strategy', 'in_footer', 'fetchpriority', 'module_dependencies' );
 	$unknown_keys = array_diff( array_keys( $args ), $allowed_keys );
-
 	if ( ! empty( $unknown_keys ) ) {
 		_doing_it_wrong(
 			$function_name,
@@ -218,7 +217,7 @@ function wp_add_inline_script( $handle, $data, $position = 'after' ) {
  *     @type string   $strategy            Optional. If provided, may be either 'defer' or 'async'.
  *     @type bool     $in_footer           Optional. Whether to print the script in the footer. Default 'false'.
  *     @type string   $fetchpriority       Optional. The fetch priority for the script. Default 'auto'.
- *     @type string[] $module_dependencies Optional. IDs for module dependencies loaded via dynamic import. Default 'array()'.
+ *     @type string[] $module_dependencies Optional. IDs for module dependencies loaded via dynamic import. Default empty array.
  * }
  * @return bool Whether the script has been registered. True on success, false on failure.
  */
@@ -399,7 +398,7 @@ function wp_deregister_script( $handle ) {
  *     @type string   $strategy            Optional. If provided, may be either 'defer' or 'async'.
  *     @type bool     $in_footer           Optional. Whether to print the script in the footer. Default 'false'.
  *     @type string   $fetchpriority       Optional. The fetch priority for the script. Default 'auto'.
- *     @type string[] $module_dependencies Optional. IDs for module dependencies loaded via dynamic import. Default 'array()'.
+ *     @type string[] $module_dependencies Optional. IDs for module dependencies loaded via dynamic import. Default empty array.
  * }
  */
 function wp_enqueue_script( $handle, $src = '', $deps = array(), $ver = false, $args = array() ) {

From ce5124fa14af2e847b6306e0da9573e1c985a39a Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 17:10:35 -0800
Subject: [PATCH 40/42] Avoid calling _wp_scripts_add_args_data() with empty
 args

---
 src/wp-includes/functions.wp-scripts.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/functions.wp-scripts.php b/src/wp-includes/functions.wp-scripts.php
index a43ae8de28e90..23ed882517ba7 100644
--- a/src/wp-includes/functions.wp-scripts.php
+++ b/src/wp-includes/functions.wp-scripts.php
@@ -417,7 +417,9 @@ function wp_enqueue_script( $handle, $src = '', $deps = array(), $ver = false, $
 		if ( $src ) {
 			$wp_scripts->add( $_handle[0], $src, $deps, $ver );
 		}
-		_wp_scripts_add_args_data( __FUNCTION__, $wp_scripts, $_handle[0], $args );
+		if ( ! empty( $args ) ) {
+			_wp_scripts_add_args_data( __FUNCTION__, $wp_scripts, $_handle[0], $args );
+		}
 	}
 
 	$wp_scripts->enqueue( $handle );

From 083287ad0103d9c91474dc770b18230f4c5463b7 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 17:24:19 -0800
Subject: [PATCH 41/42] Use WP_Scripts::add_data() instead of WP_Scripts::add()
 for _doing_it_wrong

---
 src/wp-includes/class-wp-script-modules.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/wp-includes/class-wp-script-modules.php b/src/wp-includes/class-wp-script-modules.php
index bed609c67fa60..56bc3c5d34444 100644
--- a/src/wp-includes/class-wp-script-modules.php
+++ b/src/wp-includes/class-wp-script-modules.php
@@ -575,10 +575,10 @@ private function get_import_map(): array {
 
 					if ( count( $missing_module_dependencies ) > 0 ) {
 						_doing_it_wrong(
-							WP_Scripts::class . '::add',
+							'WP_Scripts::add_data',
 							sprintf(
 								/* translators: 1: Script handle, 2: 'module_dependencies', 3: List of missing dependency IDs. */
-								__( 'The script handle "%1$s" was enqueued with script module dependencies ("%2$s") that are not registered: %3$s.' ),
+								__( 'The script with the handle "%1$s" was enqueued with script module dependencies ("%2$s") that are not registered: %3$s.' ),
 								$handle,
 								'module_dependencies',
 								implode( wp_get_list_item_separator(), $missing_module_dependencies )

From 9acd7f0a3a7a1d4c96be7d2f08dc6afed2bfb961 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@ruter.net>
Date: Fri, 30 Jan 2026 17:35:23 -0800
Subject: [PATCH 42/42] Update
 test_wp_scripts_doing_it_wrong_for_missing_script_module_dependencies

---
 tests/phpunit/tests/script-modules/wpScriptModules.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/phpunit/tests/script-modules/wpScriptModules.php b/tests/phpunit/tests/script-modules/wpScriptModules.php
index 8c3dd0af50876..f34c32b7d96d9 100644
--- a/tests/phpunit/tests/script-modules/wpScriptModules.php
+++ b/tests/phpunit/tests/script-modules/wpScriptModules.php
@@ -2102,7 +2102,7 @@ public function test_import_map_includes_dependencies_of_classic_scripts_recursi
 	 * @covers WP_Script_Modules::get_import_map
 	 */
 	public function test_wp_scripts_doing_it_wrong_for_missing_script_module_dependencies() {
-		$expected_incorrect_usage = 'WP_Scripts::add';
+		$expected_incorrect_usage = 'WP_Scripts::add_data';
 		$this->setExpectedIncorrectUsage( $expected_incorrect_usage );
 
 		wp_enqueue_script(
@@ -2137,7 +2137,7 @@ public function test_wp_scripts_doing_it_wrong_for_missing_script_module_depende
 		);
 
 		$this->assertStringContainsString(
-			'The script handle "registered-dep" was enqueued with script module dependencies ("module_dependencies") that are not registered: does-not-exist',
+			'The script with the handle "registered-dep" was enqueued with script module dependencies ("module_dependencies") that are not registered: does-not-exist',
 			$this->caught_doing_it_wrong[ $expected_incorrect_usage ],
 			'Expected _doing_it_wrong() notice to indicate missing script module dependencies for enqueued script.'
 		);