Error Cannot return null for non-nullable field "SelectedShippingMethod.carrier_code"

[ThomasHWeb]

Preconditions and environment

• Magento 2.4.7
• In my production environment, I watched this error message in logs after upgrading to Magento 2.4.7.
  It triggers because of the changes made in vendor/magento/module-quote-graph-ql/Model/Resolver/ShippingAddress/SelectedShippingMethod.php related to this commit [2.4.5] Incorrect carrier/method code on selected shipping method in GraphQL #36606.
  

Somehow, the shipping method from address has not been reset before, and the rate associate is not in the rates list. $carrierCode and $methodCode variables remain null after the foreach block.

Steps to reproduce

Not able to reproduce it in my local environment. It seems to be a very tricky use case.

Expected result

To not have selected address if last shipping method saved not matched with the new rates list.

Actual result

Cart GraphQL data are not returned in storefront because of this error.

Additional information

No response

Release note

No response

Triage and priority

• Severity: S0 - Affects critical data or functionality and leaves users without workaround.
• Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.

[m2-assistant]

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[m2-assistant]

Hi @engcom-Delta. Thank you for working on this issue.
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[engcom-Delta]

Hi @ThomasHWeb ,

Thanks for reporting and collaboration.

Verified the issue in magento 2.4.7 instance and the issue is not reproducible.

Steps to reproduce:-

1.Send a Graphql query and verify

query {
cart(cart_id: "<cart_id>") {
shipping_addresses {
selected_shipping_method {
carrier_code
method_code
}
available_shipping_methods {
carrier_code
method_code
}
}
}
}

We are not getting any error while sending the graphql query,

Please add some more details with screenshots to debug this issue.

Thanks,

[engcom-Delta]

Hi @ThomasHWeb ,

Awaiting your reply to move further on this issue.

Thanks,