[4.x]: Multiple empty carts when refreshing fast with autoSetNewCartAddresses setting

[jornwildenbeest]

What happened?

Description

New issue in favor of #3715 because the problem still exists.

When the autoSetNewCartAddresses is enabled, and you've set a default primary address in your account (yes
this only applies when you are logged in), it is possible to create multiple empty carts on refresh.

This default code from the example folder:

{% if cart is not defined %}
{% set cart = craft.commerce.carts.cart %}
{% endif %}
is creating multiple carts when you have the autoSetNewCartAddresses setting enabled and you've setup a default primary address. This happens when you refresh several times in a row. You have to refresh fast but apparently customers are doing this because we are seeing multiple empty carts in our shop.

This only happens when the user has no active carts.

When debugging I found out that this is caused because of the autoSetNewCartAddresses setting. This is causing a save on first reload when you have no active cart. So when reloading multiple times it creates multiple

carts:

Steps to reproduce

1. Do a clean install with craft 4.x and copy the commerce example-templates
2. Create a account and log in.
3. Set a default primary address
4. Open a tab with the /shop/ page.
5. Clear all active carts
6. Go to the /shop/ tab and refresh fast, like multiple times per second
7. You will see multiple empty active carts in the control panel tied to the same user.

Expected behavior

The expected behavior is that Craft Commerce only creates 1 cart.

Actual behavior

Craft Commerce creates multiple empty carts.

Craft CMS version

4.14.14

Craft Commerce version

4.8.3

PHP version

8.2

Operating system and version

Mac os 15.2 (24C101)

Database type and version

MySQL 8

Image driver and version

No response

Installed plugins and versions

• Craft Commerce

[linear]

PT-2728 [4.x]: Multiple empty carts when refreshing fast with autoSetNewCartAddresses setting

[lukeholder]

Thanks, we can reproduce this with your steps.

It would good to know how many of these duplicates get created per user?

Is it all users who land in the store, or just those manually refreshing? Or, is it due to some front-end code that is calling getCart() multiple times on the same page in twig (or via Ajax requests)?

How do these extra carts affect your project? Does it cause errors in custom code, or just annoying to see the duplicates carts in reporting etc?

[jornwildenbeest]

@lukeholder,

In our case, it is mostly 3 to 5 carts per user, and in some unique cases 8, 10 or even 46.
But there are also a lot of users that only have 1 cart (this is what you would expect).

Not sure, I've only been able to reproduce this when refreshing manually, and I can imagine that people are doing this when the shop is a bit slow for example. So I would say, only when you are manually refreshing.

I've tried to rule out all of our custom code by trying this in a fresh new install, with only one .getCart() in the twig code. That's when I realized that this wasn't caused by our own code. Not sure about any Ajax requests.. If Craft does this by default then yes this is possible, but not that I know of.

We have seen cases in our project where people just lose their cart at a certain moment, but I can't tell you if that is because of Craft's code, or any of our custom plugins.
But I can that this happend a handful of times, so it is mostly annoying to see the duplicates, but maybe there are still underlying issues we do not know of.

[lukeholder]

We will keep this ticket open and see if others are also experiencing this before diving into it further. @jornwildenbeest have you gotten a lot of these duplicates in production recently?

[jornwildenbeest]

@lukeholder, Yes we are still seeing more duplicates.

is there anything we could do in the meantime to prevent these duplicate carts?
Our client is worried it might interfere with the order process, because we are still not a 100% sure it if it causing any bugs or not.

[lukeholder]

@jornwildenbeest it wont be interfering with anything from the customers perspective, the last cart created and saved in their session/cookie will be their cart from additional requests. It is more annoying for the backend store admin seeing empty carts. We will keep monitoring it and do some testing on our side.