Last Updated: 2024-04-18

Never bind a variable only in if branches.

<?php

        if ($cart->isFree()) {
            $appointment = $cart->redeemFreebieIfAvailable();
        }

        if ($unusedTicket) {
            $appointment = $cart->useTicketToBookAppointment($unusedTicket);
        }

        // FIXME: In the double-payment edge case here, there is no appointment
        // model available, therefore this will fail.
        if ($cart->fresh()->paid) {
            if ($appointment) {

This gave an error appointment undefined sometimes - i.e. when neither condition was true.

I should have set the appointment to null first

<?php

  $appoinment = null;