Delete the product in the cart, if the same product added in Woocommerce

There are methods that empty the cart if you add a new product.

function wdm_empty_cart( $cart_item_data, $product_id, $variation_id ) 
{ 

global $woocommerce;
$woocommerce->cart->empty_cart();
}

But what I want is only if you add the same product. So adding if ( $in_cart ) does the job but I also do not want to empty whole cart.

Just want to delete the same product that added previously and keep the others.

I mean overwrite.

Answer

You can use woocommerce_add_to_cart_validation action hooks and check against products that are already in the cart. code will go in your active theme functions.php file.

add_filter('woocommerce_add_to_cart_validation', 'remove_cart_item_before_add_to_cart', 1, 3);
function remove_cart_item_before_add_to_cart($passed, $product_id, $quantity) {
    
    $already_in_cart = false;
    
    foreach( WC()->cart->get_cart() as $key => $item ){
        // Check if the item is already is in cart.
        if( $item['product_id'] == $product_id ){
            $already_in_cart = true;
            $existing_product_key = $key;
            break;
        }
    }

    if( $already_in_cart  ){
        WC()->cart->remove_cart_item($existing_product_key);
    }
    
    return $passed;
}