Call to a member function stripe() on null (soft deletes)

[larskoole]

Cashier Stripe Version

16.0.4

Laravel Version

latest

PHP Version

8.4

Database Driver & Version

No response

Description

When receiving a webhook for a soft deleted billable model you get the error:
Call to a member function stripe() on null

What going good is the fact that Cashier::findBillable() applies withTrashed() to find the soft deleted model inside of the WebhookController.

Where it's going wrong is in the asStripeSubscriptionItem() method of SubscriptionItem looking back to the owner like so:

public function asStripeSubscriptionItem(array $expand = [])
{
    return $this->subscription->owner->stripe()->subscriptionItems->retrieve(
        $this->stripe_id, ['expand' => $expand]
    );
}

This method is called from $subscription->currentPeriodEnd(); which does $item->currentPeriodEnd();, which calls $this->asStripeSubscriptionItem().

Here it loads the subscription, but it can't find the owner because it's soft deleted and there is no withTrashed() applied on the subscription->owner relation.

I think a solution would be to chaperone the subscription + owner to the SubscriptionItem, or add withTrashed() logic to the subscription->owner relation.

Steps To Reproduce

1. Grab a starter kit
2. Add soft deletes to a user
3. Start a subscription
4. Delete the user
5. Cancel the subscription

[larskoole]

Today I found out that when calling soft deleted BelongsTo relations from non soft deleted models does actually work.
Weirdly enough it doesn't work for the case above.

I'm overriding the Subscription class in our application with the following method:

public function currentPeriodEnd(DateTimeZone|string|int|null $timezone = null): ?CarbonInterface
{
    if (!$this->relationLoaded('items.subscription.owner')) {
        $this->load(['items.subscription.owner' => function (BelongsTo $query) {
            $query->withTrashed();
        }]);
    }
    $items = $this->items;
    if ($items->isEmpty()) {
        return null;
    }
    $latestEnd = null;
    foreach ($items as $item) {
        $itemEnd = $item->currentPeriodEnd();
        if ($itemEnd && (!$latestEnd || $itemEnd->gt($latestEnd))) {
            $latestEnd = $itemEnd;
        }
    }
    return $latestEnd ? ($timezone ? $latestEnd->setTimezone($timezone) : $latestEnd) : null;
}

When I fired the event again from within the Stripe dashboard it actually worked.

Seems like something here isn't working as intended, eager loading the relation or chaperoning it shouldn't be the solution.