Inconsistent Behavior of `transaction_changed_attributes` with `store_accessor`

[rohithmsr]

Hi @dylanahsmith @byroot ,

I recently encountered an unexpected behaviour with transaction_changed_attributes.

I’m using ActiveRecord::Store, which provides the store_accessor method. This allows keys in a JSON column to be treated like regular attributes. For instance, in a model (let's call it Subscription), there’s a details JSON field that stores data like start_date and account_id. By defining accessors for these keys, they can be interacted with as normal attributes. More details can be found here

Issue

When updating the start_date nested field directly using:

subscription.update!(details: { "start_date" => "2021-10-23" })  

the change is correctly captured in transaction_changed_attributes.

However, when updating the same field using the store_accessor method:

subscription.update!(start_date: "2019-10-23")  

the change does not get captured in transaction_changed_attributes.

Question

This discrepancy becomes problematic when my logic relies on detecting these changes. Is this behaviour a known limitation, or could I be missing something? I’d greatly appreciate any insights or suggestions you might have!