RemoveFromCartEvent occasionally WSOD

@nicxvan , I have fixed the issue and created Patch

The last submitted patch, 3: google_tag-3424695.patch, failed testing. View results →
- codesniffer_fixes.patch Interdiff of automated coding standards fixes only.

Is there any chance you can put that into a merge request?

I did some local testing I have not pushed up yet and I think there is a simpler fix where we assert the order is an Drupal\commerce_order\Entity\OrderInterface rather than just asserting it is !null.

I think this should be checked and solved in combination with the other commerce related issues?

I haven't been able to test this on my client yet, but just looking at the code this is not fixed:

https://git.drupalcode.org/project/google_tag/-/blob/2.0.x/src/Plugin/Go...

That line is what throws the error and there are no new protections.

I think the patch does quite a bit more than needed, I think we just need to call:

$order_item->getOrder()
then assert that it's an OrderInterface before moving on.

Nominally this patch seems to do the same, but rather than just exiting they try to pass as much info as exists.

I think if the event is incomplete not sending the event is probably better, let me know which direction you would like to go.

Pushing a quick assertion as POC. I still need to review tests.

I'm hiding the patch since it seems to make a lot of unnecessary changes.

I'm having a similar issue but assert already exists there

The website encountered an unexpected error. Please try again later.
Error: Call to a member function subtract() on null in Drupal\google_tag\Plugin\GoogleTag\Event\Commerce\AddToCartEvent->getData() (line 44 of modules/contrib/google_tag/src/Plugin/GoogleTag/Event/Commerce/AddToCartEvent.php).
Drupal\google_tag\Plugin\GoogleTag\Event\Commerce\AddToCartEvent->getData() (Line: 147)
google_tag_page_attachments(Array) (Line: 315)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}(Object, 'google_tag') (Line: 405)
Drupal\Core\Extension\ModuleHandler->invokeAllWith('page_attachments', Object) (Line: 316)
Drupal\Core\Render\MainContent\HtmlRenderer->invokePageAttachmentHooks(Array) (Line: 289)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 580)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 290)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 132)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object, Object) (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object, 'kernel.view', Object)
call_user_func(Array, Object, 'kernel.view', Object) (Line: 142)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.view') (Line: 174)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 81)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 718)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

I'm facing the same issue in the AddToCartEvent class. I rolled back the fix in the merge request and applied the same changes to AddToCartEvent

If there is an existing MR please apply your changes to the MR.

Technically those changes are out of scope of this issue since it's a different event. If you want to increase the scope please update the Issue summary and review this issue so we can get it merged.

Regarding comment #10, I had the same issue when handling order items for which the price was not calculated yet, so I created issue #3489811 🐛 AddToCartEvent WSOD for order items with no price Active

Removing assert() from patch #11 and replace it with if statement.
why did I removed the assert() because on Production the zend.assertions will be -1 (at most cases) so assert won't be working as expected.
I got the error on AddToCartEvent.

Error: Error: Call to a member function getStore() on null in Drupal\google_tag\Plugin\GoogleTag\Event\Commerce\AddToCartEvent->getData() (line 45 of /app/docroot/modules/contrib/google_tag/src/Plugin/GoogleTag/Event/Commerce/AddToCartEvent.php).

with the assert() applied.

Use the MR please.

Also your patch does not do what you describe.

Looks like we weren't sure how this was happening, perhaps this will help- at least for one case.

Since orders and carts are the same thing in commerce, I'm going to refer to both as order.

When a user is anonymous and has something in their order, then logs in- there is an order process that takes place... going through the code...

I'm an anonymous user, order #x, log in, my user has an existing draft order, so #x is merged into the existing order, #x is deleted.

Our Google_Tag RemoveFromCartEvent is fired in CommerceCartSubscriber, on the CartEvents::CART_ORDER_ITEM_REMOVE event... which is fired in CartManager->removeOrderItem.

removeOrderItem: order item is deleted, order item is removed from the order, CartEvents::CART_ORDER_ITEM_REMOVE is fired. If there are no more order items, the order is emptied. I don't immediately see any delete of the order taking place, but it disappeared from my database- so it was deleted. Doesn't really matter for the solve... maybe...

The issue here is that the event is fired after the order item is deleted in the CartManager->removeOrderItem, line 159. Just glancing at the code, I would think the $order_item would still be passed... oh it is, the issue is the getOrder() call.

Meaning the issue is when the order is deleted and merged into the existing cart... extremely likely that the order item is now referencing an order id that doesn't exist, so getOrder() returns null and crashy crash.

My guess is that moving the event fire, before the order item remove, would resolve the issue; but I'd want to investigate a little further. I wasn't able to find the order merge process right away... nevermind I did trip over it. Class is OrderAssignment, assign method.

It fires its event before modifying data, which is likely what we need to do here, there is even a comment specifically mentioning that reason.

I did not track down the order deletion, however I suspect the issue is the order item has lost its order reference id, before the event is fired, due to either the order item delete, or cart remove item. Regardless of how, the order item reference to its order is gone because our event is firing too late, in the Cart Manager. We can't get the affiliation in this specific case.