Add an empty list block v2

lib/compat/experimental/blocks.php

@@ -159,3 +159,14 @@ function ( $response ) {
 	}
 }
 add_action( 'rest_api_init', 'gutenberg_rest_comment_set_children_as_embeddable' );
+
+/**
+ * Sets a global JS variable used to trigger the availability of the experimental list block.
+ */
+function gutenberg_enable_experimental_list_block() {
+	if ( get_option( 'gutenberg-experiments' ) && array_key_exists( 'gutenberg-list-v2', get_option( 'gutenberg-experiments' ) ) ) {
+		wp_add_inline_script( 'wp-block-library', 'window.__experimentalEnableListBlockV2 = true', 'before' );
+	}
+}
+
+add_action( 'admin_init', 'gutenberg_enable_experimental_list_block' );

lib/experiments-page.php

@@ -51,6 +51,17 @@ function gutenberg_initialize_experiments_settings() {
 			'id'    => 'gutenberg-navigation',
 		)
 	);
+	add_settings_field(
+		'gutenberg-list-v2',
+		__( 'List block v2', 'gutenberg' ),
+		'gutenberg_display_experiment_field',
+		'gutenberg-experiments',
+		'gutenberg_experiments_section',
+		array(
+			'label' => __( 'Test a new list block that uses nested list item blocks (Warning: The new block is not ready. You may experience content loss, avoid using it on production sites)', 'gutenberg' ),
+			'id'    => 'gutenberg-list-v2',
+		)
+	);
 	register_setting(
 		'gutenberg-experiments',
 		'gutenberg-experiments'

packages/block-library/src/list/index.js

@@ -11,12 +11,13 @@ import edit from './edit';
 import metadata from './block.json';
 import save from './save';
 import transforms from './transforms';
+import settingsV2 from './v2';
 
 const { name } = metadata;
 
 export { metadata, name };
 
-export const settings = {
+const settingsV1 = {
 	icon,
 	example: {
 		attributes: {
@@ -41,3 +42,7 @@ export const settings = {
 	save,
 	deprecated,
 };
+
+export const settings = window?.__experimentalEnableListBlockV2
+	? settingsV2
+	: settingsV1;

packages/block-library/src/list/v2/edit.js

@@ -0,0 +1,5 @@
+function Edit() {
+	return <div>List block v2</div>;
+}
+
+export default Edit;

packages/block-library/src/list/v2/index.js

@@ -0,0 +1,18 @@
+/**
+ * WordPress dependencies
+ */
+import { list as icon } from '@wordpress/icons';
+
+/**
+ * Internal dependencies
+ */
+import edit from './edit';
+import save from './save';
+
+const settings = {
+	icon,
+	edit,
+	save,
+};
+
+export default settings;

packages/block-library/src/list/v2/save.js

@@ -0,0 +1,5 @@
+function Save() {
+	return <div>List block v2</div>;
+}
+
+export default Save;