Plugin: Deprecate gutenberg_get_script_polyfill

docs/designers-developers/developers/backward-compatibility/deprecations.md

@@ -57,6 +57,7 @@ The Gutenberg project's deprecation policy is intended to support backward compa
 - The PHP function `gutenberg_toggle_custom_fields` has been removed.
 - The PHP function `gutenberg_collect_meta_box_data` has been removed. Use [`register_and_do_post_meta_boxes`](https://developer.wordpress.org/reference/functions/register_and_do_post_meta_boxes/) instead.
 - `window._wpLoadGutenbergEditor` has been removed. Use `window._wpLoadBlockEditor` instead. Note: This is a private API, not intended for public use. It may be removed in the future.
+- The PHP function `gutenberg_get_script_polyfill` has been removed. Use [`wp_get_script_polyfill`](https://developer.wordpress.org/reference/functions/wp_get_script_polyfill/) instead.
 
 ## 4.5.0
 - `Dropdown.refresh()` has been deprecated as the contained `Popover` is now automatically refreshed.

lib/client-assets.php

@@ -43,27 +43,10 @@ function gutenberg_url( $path ) {
  * @return string Conditional polyfill inline script.
  */
 function gutenberg_get_script_polyfill( $tests ) {
-	global $wp_scripts;
-
-	$polyfill = '';
-	foreach ( $tests as $test => $handle ) {
-		if ( ! array_key_exists( $handle, $wp_scripts->registered ) ) {
-			continue;
-		}
-
-		$polyfill .= (
-			// Test presence of feature...
-			'( ' . $test . ' ) || ' .
-			// ...appending polyfill on any failures. Cautious viewers may balk
-			// at the `document.write`. Its caveat of synchronous mid-stream
-			// blocking write is exactly the behavior we need though.
-			'document.write( \'<script src="' .
-			esc_url( $wp_scripts->registered[ $handle ]->src ) .
-			'"></scr\' + \'ipt>\' );'
-		);
-	}
+	_deprecated_function( __FUNCTION__, '5.0.0', 'wp_get_script_polyfill' );
 
-	return $polyfill;
+	global $wp_scripts;
+	return wp_get_script_polyfill( $wp_scripts, $tests );
 }
 
 if ( ! function_exists( 'register_tinymce_scripts' ) ) {
@@ -153,11 +136,14 @@ function gutenberg_register_packages_scripts() {
  * @since 0.1.0
  */
 function gutenberg_register_scripts_and_styles() {
+	global $wp_scripts;
+
 	gutenberg_register_vendor_scripts();
 
 	wp_add_inline_script(
 		'wp-polyfill',
-		gutenberg_get_script_polyfill(
+		wp_get_script_polyfill(
+			$wp_scripts,
 			array(
 				'\'fetch\' in window' => 'wp-polyfill-fetch',
 				'document.contains'   => 'wp-polyfill-node-contains',