WP_Theme::is_block_theme() WordPress Method

	public function is_block_theme() {
		$paths_to_index_block_template = array(
			$this->get_file_path( '/block-templates/index.html' ),
			$this->get_file_path( '/templates/index.html' ),
		);

		foreach ( $paths_to_index_block_template as $path_to_index_block_template ) {
			if ( is_file( $path_to_index_block_template ) && is_readable( $path_to_index_block_template ) ) {
				return true;
			}
		}

		return false;
	}