Add to version control would help

lib/block-template-utils.php

@@ -0,0 +1,114 @@
+<?php
+/**
+ * Utilities used to fetch and create templates and template parts.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Creates an export of the current templates and
+ * template parts from the site editor at the
+ * specified path in a ZIP file.
+ *
+ * @since 5.9.0
+ * @since 6.0.0 Adds the whole theme to the export archive.
+ *
+ * @global string $wp_version The WordPress version string.
+ *
+ * @return WP_Error|string Path of the ZIP file or error on failure.
+ */
+function gutenberg_generate_block_templates_export_file() {
+	global $wp_version;
+
+	if ( ! class_exists( 'ZipArchive' ) ) {
+		return new WP_Error( 'missing_zip_package', __( 'Zip Export not supported.' ) );
+	}
+
+	$obscura    = wp_generate_password( 12, false, false );
+	$theme_name = basename( get_stylesheet() );
+	$filename   = get_temp_dir() . $theme_name . $obscura . '.zip';
+
+	$zip = new ZipArchive();
+	if ( true !== $zip->open( $filename, ZipArchive::CREATE | ZipArchive::OVERWRITE ) ) {
+		return new WP_Error( 'unable_to_create_zip', __( 'Unable to open export file (archive) for writing.' ) );
+	}
+
+	$zip->addEmptyDir( 'templates' );
+	$zip->addEmptyDir( 'parts' );
+
+	// Get path of the theme.
+	$theme_path = wp_normalize_path( get_stylesheet_directory() );
+
+	// Create recursive directory iterator.
+	$theme_files = new RecursiveIteratorIterator(
+		new RecursiveDirectoryIterator( $theme_path ),
+		RecursiveIteratorIterator::LEAVES_ONLY
+	);
+
+	// Make a copy of the current theme.
+	foreach ( $theme_files as $file ) {
+		// Skip directories as they are added automatically.
+		if ( ! $file->isDir() ) {
+			// Get real and relative path for current file.
+			$file_path     = wp_normalize_path( $file );
+			$relative_path = substr( $file_path, strlen( $theme_path ) + 1 );
+
+			if ( ! wp_is_theme_directory_ignored( $relative_path ) ) {
+				$zip->addFile( $file_path, $relative_path );
+			}
+		}
+	}
+
+	// Load templates into the zip file.
+	$templates = gutenberg_get_block_templates();
+	foreach ( $templates as $template ) {
+		$template->content = traverse_and_serialize_blocks(
+			parse_blocks( $template->content ),
+			'_remove_theme_attribute_from_template_part_block'
+		);
+
+		$zip->addFromString(
+			'templates/' . $template->slug . '.html',
+			$template->content
+		);
+	}
+
+	// Load template parts into the zip file.
+	$template_parts = gutenberg_get_block_templates( array(), 'wp_template_part' );
+	foreach ( $template_parts as $template_part ) {
+		$zip->addFromString(
+			'parts/' . $template_part->slug . '.html',
+			$template_part->content
+		);
+	}
+
+	// Load theme.json into the zip file.
+	$tree = WP_Theme_JSON_Resolver_Gutenberg::get_theme_data( array(), array( 'with_supports' => false ) );
+	// Merge with user data.
+	$tree->merge( WP_Theme_JSON_Resolver_Gutenberg::get_user_data() );
+
+	$theme_json_raw = $tree->get_data();
+	// If a version is defined, add a schema.
+	if ( $theme_json_raw['version'] ) {
+		$theme_json_version = 'wp/' . substr( $wp_version, 0, 3 );
+		$schema             = array( '$schema' => 'https://schemas.wp.org/' . $theme_json_version . '/theme.json' );
+		$theme_json_raw     = array_merge( $schema, $theme_json_raw );
+	}
+
+	// Convert to a string.
+	$theme_json_encoded = wp_json_encode( $theme_json_raw, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE );
+
+	// Replace 4 spaces with a tab.
+	$theme_json_tabbed = preg_replace( '~(?:^|\G)\h{4}~m', "\t", $theme_json_encoded );
+
+	// Add the theme.json file to the zip.
+	$zip->addFromString(
+		'theme.json',
+		$theme_json_tabbed
+	);
+
+	// Save changes to the zip file.
+	$zip->close();
+
+	return $filename;
+}

lib/class-wp-rest-edit-site-export-controller-gutenberg.php

@@ -4,7 +4,7 @@
  * and template parts.
  *
  * This class extension exists so that theme exporting takes into account any updates/changes to
- * WP_Theme_JSON_Gutenberg or WP_Theme_JSON_Resolver_Gutenberg or related.
+ * WP_Theme_JSON_Gutenberg, WP_Theme_JSON_Resolver_Gutenberg or related classes.
  *
  * @package    gutenberg
  * @subpackage REST_API