Redirect to cart if last item is removed from checkout

redirect.php

// REDIRECT TO SHOP ON EMPTY CHECKOUT

add_action( 'wp_footer', function() {
	if ( is_checkout() ) {
		$redirect_page_id = get_option( 'bbcpqcp_redirect', wc_get_page_id( 'shop' ) ); // or 'cart'
		$redirect_page = get_permalink( $redirect_page_id );
		?>
		<script>
		jQuery( function($){
			jQuery(document.body).on( 'updated_checkout', function(event) { 
				var cart_item_count = 0;
				var qty_field_inputs = document.getElementsByClassName("qty");
				for (var i = 0; i < qty_field_inputs.length; i++) {
					cart_item_count = cart_item_count + Number( qty_field_inputs.item(i).value );
				}

				if ( 0 == cart_item_count ) {
					location.href = '<?php echo $redirect_page; ?>';
				}
			});
		});
		</script>
		<?php
	}
});

// CHECKOUT PATCH FOR CHANGE CHECKOUT QUANTITY PLUGIN

add_action( 'woocommerce_review_order_after_submit', function() {
	echo '<input id="qtyhidden" type="hidden" name="qtyhidden" value="check">';
	wc_enqueue_js( "
		$(document).on('change','input[name^=\'shipping_method_qty\']',function(){
			$('#qtyhidden').val($(this).parent().next().val()+':'+$(this).val());
		});
	");
});

add_action( 'woocommerce_checkout_update_order_review', function( $post_data ) {
	parse_str( $post_data, $post_data_array_2 );
	$updated_qty = false;
	foreach ( $post_data_array_2 as $key => $value ) {   
		if ( $key == 'qtyhidden' && $value !== 'check' ) {
			$values = explode( ':', $value );
			WC()->cart->set_quantity( $values[0], $values[1], false );
			$updated_qty = true;
		}      
	}   
	if ( $updated_qty ) {
        	WC()->cart->calculate_totals();
    	}
});