Why does `current_store_id` default to `nil`?

[fsateler]

Hi,

I was bit recently by a bug because a thread (created by a library) did not properly initialize current_store_id. I added a monkey patch to add that, and all is working well now.

However, this got me thinking: why is it possible for current_store_id to ever return nil? I believe the safer default is to always set to SecureRandom.uuid if uninitialized:

def current_store_id
  Thread.current.fetch(REQUEST_STORE_ID) { SecureRandom.uuid }
end

The current default basically makes all the spawned threads share a store between them, but separate from the main thread.

It may be an even safer default to raise an error when the request store is unset. It probably means a thread was spawned without proper setup/teardown

[ElMassimo]

Hi Felipe, that's a good observation.

• The current behavior is definitely not desirable
• Using SecureRandom.uuid might cover up problems when threads are not properly initialized
• A potential problem with raising an error, is that it would stop working in non-request lifecycles (for example, in a console)

A possible solution would be to have the main thread use true unless specified, and raise an error for any child threads that are not explicitly initialized.

Thanks!