Fix Mini Cart template part link on WP 5.9 (https://github.com/woocommerce/woocommerce-blocks/pull/5348)

* Fix link to edit the Mini Cart template part in WP 5.9

* Use wp_is_block_theme() function

* Add protection against overwriting isSiteEditorAvailable setting

* Rename isSiteEditorAvailable to isBlockTheme

plugins/woocommerce-blocks/assets/js/blocks/cart-checkout/mini-cart/edit.tsx

@@ -58,7 +58,7 @@ const MiniCartBlock = ( {
 
 	const themeSlug = getSetting( 'themeSlug', '' );
 
-	const isSiteEditorAvailable = getSetting( 'isSiteEditorAvailable', false );
+	const isBlockTheme = getSetting( 'isBlockTheme', false );
 
 	/**
 	 * @todo Replace `getColorClassName` and manual style manipulation with
@@ -139,7 +139,7 @@ const MiniCartBlock = ( {
 						}
 					/>
 				</PanelBody>
-				{ isSiteEditorAvailable &&
+				{ isBlockTheme &&
 					isString( themeSlug ) &&
 					themeSlug.length > 0 && (
 						<PanelBody
@@ -150,9 +150,8 @@ const MiniCartBlock = ( {
 						>
 							<ExternalLink
 								href={ addQueryArgs(
-									`${ ADMIN_URL }themes.php`,
+									`${ ADMIN_URL }site-editor.php`,
 									{
-										page: 'gutenberg-edit-site',
 										postId: `${ themeSlug }//mini-cart`,
 										postType: 'wp_template_part',
 									}

plugins/woocommerce-blocks/src/BlockTypes/MiniCart.php

@@ -177,17 +177,17 @@ class MiniCart extends AbstractBlock {
 			''
 		);
 
-		if ( function_exists( 'gutenberg_experimental_is_site_editor_available' ) ) {
+		if ( function_exists( 'wp_is_block_theme' ) ) {
 			$this->asset_data_registry->add(
-				'isSiteEditorAvailable',
-				gutenberg_experimental_is_site_editor_available(),
-				false
+				'isBlockTheme',
+				wp_is_block_theme(),
+				true
 			);
 		} else {
 			$this->asset_data_registry->add(
-				'isSiteEditorAvailable',
+				'isBlockTheme',
 				false,
-				false
+				true
 			);
 		}