Build: Enable React Fast Refresh for block development

Brings the same functionality introduced in the Gutenberg plugin with WordPress/gutenberg#28273. In effect, it brings React Fast Refresh support to WordPress core for block development with `@wordpress/scripts`.

Props walbo, antonvlasenko.
See #51750, #55505.
Follow-up [53135].


Built from https://develop.svn.wordpress.org/trunk@53140


git-svn-id: http://core.svn.wordpress.org/trunk@52729 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/assets/script-loader-react-refresh-entry.php

@@ -0,0 +1 @@
+<?php return array('dependencies' => array('wp-react-refresh-runtime'), 'version' => '8151afc94a5ebc73b7a8229f0d7ee352');

wp-includes/assets/script-loader-react-refresh-runtime.php

@@ -0,0 +1 @@
+<?php return array('dependencies' => array(), 'version' => '4fb86f241c3b2d9d9e0411b507079823');

wp-includes/script-loader.php

@@ -214,6 +214,45 @@ function wp_get_script_polyfill( $scripts, $tests ) {
 	return $polyfill;
 }
 
+/**
+ * Registers development scripts that integrate with `@wordpress/scripts`.
+ *
+ * @see https://github.com/WordPress/gutenberg/tree/trunk/packages/scripts#start
+ *
+ * @since 6.0.0
+ *
+ * @param WP_Scripts $scripts WP_Scripts object.
+ */
+function wp_register_development_scripts( $scripts ) {
+	if (
+		! defined( 'SCRIPT_DEBUG' ) || ! SCRIPT_DEBUG
+		|| empty( $scripts->registered['react'] )
+	) {
+		return;
+	}
+
+	$development_scripts = array(
+		'react-refresh-entry',
+		'react-refresh-runtime',
+	);
+
+	foreach ( $development_scripts as $script_name ) {
+		$assets = include ABSPATH . WPINC . '/assets/script-loader-' . $script_name . '.php';
+		if ( ! is_array( $assets ) ) {
+			return;
+		}
+		$scripts->add(
+			'wp-' . $script_name,
+			'/wp-includes/js/dist/development/' . $script_name . '.js',
+			$assets['dependencies'],
+			$assets['version']
+		);
+	}
+
+	// See https://github.com/pmmmwh/react-refresh-webpack-plugin/blob/main/docs/TROUBLESHOOTING.md#externalising-react.
+	$scripts->registered['react']->deps[] = 'wp-react-refresh-entry';
+}
+
 /**
  * Registers all the WordPress packages scripts that are in the standardized
  * `js/dist/` location.
@@ -560,6 +599,7 @@ function wp_tinymce_inline_scripts() {
  */
 function wp_default_packages( $scripts ) {
 	wp_default_packages_vendor( $scripts );
+	wp_register_development_scripts( $scripts );
 	wp_register_tinymce_scripts( $scripts );
 	wp_default_packages_scripts( $scripts );
 

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.0-alpha-53139';
+$wp_version = '6.0-alpha-53140';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.