[MarketShip] Enable USPS flat rate services by default

marketship-enable-flat-rate-services.php

<?php

/**
 * Filters the default value of the marketship_shippo_usps_settings
 * user meta key to enable flat rate services by default.
 *
 * @param mixed  $value    Meta value.
 * @param int    $user_id  User ID.
 * @param string $meta_key Meta key.
 * @param bool   $single   Whether to return a single value.
 *
 * @return array|string
 */
function marketship_filter_default_usps_settings( $value, $user_id, $meta_key, $single ) {
	if ( 'marketship_shippo_usps_settings' !== $meta_key ) {
        return $value;
    }

    $default_settings = array(
        'enable_flat_rate_services' => 'yes',
    );

    return $single ? $default_settings : array( $default_settings );
}

add_filter( 'default_user_metadata', 'marketship_filter_default_usps_settings', 10, 4 );