Simple Sales Tax: Charge tax on composite products

sst-set-composite-product-price.php

<?php

/**
 * Sets the taxable price for all Composite Products to the product price.
 * This overrides the default behavior of Simple Sales Tax, which is to tax
 * the components of a Composite Product and not the product itself.
 *
 * This hook MUST run with priority 11 or later to work properly.
 *
 * @see SST_Composite_Products::filter_composite_product_price()
 *
 * @param float      $price   Product price for tax calculation purposes.
 * @param WC_Product $product Product.
 *
 * @return float
 */
function sst_set_composite_product_price( $price, $product ) {
    if ( is_a( $product, 'WC_Product_Composite' ) ) {
        $price = $product->get_price();
    }

    return $price;
}

add_filter( 'wootax_product_price', 'sst_set_composite_product_price', 20, 2 );