Only one currently added product into Woocommerce cart?

Question

I would like Woocommerce to only allow 1 product in the cart. If a product is already in the cart and another one is added then it should remove the previous one.

I foun

Answer 1

This one is the more compact and actual code as global $woocommerce is not needed anymore:

add_filter( 'woocommerce_add_to_cart_validation', 'auto_empty_cart', 20, 3 );
function auto_empty_cart( $passed, $product_id, $quantity ) {
    if( WC()->cart->is_empty() ) return $passed; // Exit

    WC()->cart->empty_cart();
    return $passed;
}

Code goes in function.php file of your active child theme (or active theme).

Tested and works in all Woocommerce versions since 2.6.x