We have a Linear issue: https://linear.app/comm/issue/ENG-2128/display-alert-when-sensitivedatacleaner-is-activated that requires to display alert when database is deleted. Since task cancellation is closely related to database deletion, shouldn't we also display some kind if alert when such an exception is thrown?

Is it possible that e will ever be TASK_CANCELLED here? Task cancellation occurs when we delete database. Database is deleted in this component. Database queries in this component are awaited sequentially before and after database deletion query. Not sue whether it is possible that database tasks issued inside this component can ever be cancelled.

This will prevent SQLiteContextProvider from running its functionality until the app is restarted. Are we sure it is what we want?

This flag is copied from C++ code introduced in previous differentials in this stack. Ideally it would be an attribute of GlobalDBSingleton that CommCoreModule would expose to JavaScript via some getter method. It would eliminate the coupling in the codebase. Nevertheless it is hard to estimate how much work it would be and this diff stack is a solution to a high priority Linear task so landing should not be blocked on implementing a getter method mentioned above.

I think you are right. Displaying an alert in this case wouldn't bring much more information than the alert we display in the case of database deletion.

To be honest no one can be sure if and when we will decide to call clearSensitiveData fro other places in the code. But I recall @ashoat mentioning the possibility of calling clearSensitiveData from other places to justify usage of scheduleOrRunCancellableCommonImpl on iOS before JS thread starts. That said I agree with your point about introducing this check here.

Creating a task for this is a good idea. You do not need to do it now, but please make sure you create it and link it in the diff prior to landing.

Sorry, I forgot to mention this later but in fact, there is an exact situation when we will use clearSensitiveData in a different place - when database initialization will fail because we e.g. will be unable to perform database migration we will call this to re-create the database.

Yes, this is exactly what we want. If the database is being deleted, that means the user is being logged out. If the user is being logged out, we have nothing to fetch from SQLite.

It's honestly a bit concerning that this isn't clear to the team working on this at this point... I've written about it here, here, and in this comment:

Also note that SQLiteContextProvider should ALWAYS only run once, and should ALWAYS run exactly when the app starts. If the app starts while the user is logged in but then a logout is initiated, then SQLiteContextProvider might see a special exception thrown (see ENG-2139)… in that case, it should "give up" and just call setStoreLoaded(true).

It's critically important that the team here groks what we're doing and why. If you're basically treating this as "take Ashoat's requirements and implement them", then you will keep getting confused like this.