BEM Wp menu (by Ira Beskor)

functions.php

/*-------------- Creating custom menu with BEM classes  ----------------*/

// Change main menu parameters
add_filter( 'wp_nav_menu_args', 'filter_wp_menu_args' );
function filter_wp_menu_args( $args ) {
	if ( $args['theme_location'] === 'header-menu' || 'blog-menu' ) {
		$args['container']  = false;
		$args['items_wrap'] = '<ul class="%2$s">%3$s</ul>';
		$args['menu_class'] = 'menu__list';
	}
	return $args;
}
// Change id of li
add_filter( 'nav_menu_item_id', 'filter_menu_item_css_id', 10, 4 );
function filter_menu_item_css_id( $menu_id, $item, $args, $depth ) {
	return $args->theme_location === 'header-menu' || 'blog-menu' ? '' : $menu_id;
}
// Change class of li
add_filter( 'nav_menu_css_class', 'filter_nav_menu_css_classes', 10, 4 );
function filter_nav_menu_css_classes( $classes, $item, $args, $depth ) {
	if ( $args->theme_location === 'header-menu' || 'blog-menu' ) {
		$classes = [
			'menu__list-item',
		];
		if ( $item->current ) {
			$classes[] = 'menu__list-item--active';
		}
	}
	return $classes;
}

// Add classes to links
add_filter( 'nav_menu_link_attributes', 'filter_nav_menu_link_attributes', 10, 4 );
function filter_nav_menu_link_attributes( $atts, $item, $args, $depth ) {
	if ( $args->theme_location === 'header-menu' || 'blog-menu' ) {
		$atts['class'] = 'menu__link';
		if ( $item->current ) {
			$atts['class'] .= ' menu__link--active';
		}
	}
    
	return $atts;
}

// Change class of submenu ul
add_filter( 'nav_menu_submenu_css_class', 'filter_nav_menu_submenu_css_class', 10, 3 );
function filter_nav_menu_submenu_css_class( $classes, $args, $depth ) {
    if ( $args->theme_location === 'header-menu' ) {
        $classes = [
            'menu__submenu-list',
        ];
    }
    return $classes;
}

/*-------------- End of creating custom menu  ----------------*/