Added notification observer to new instances of mainQueueContext

[jimabc]

After calling resetStore in CoreDataStack the mainQueueContext loses its ability to save changes upstream because the existing notification observer is for the previous instance.

[rcedwards]

Ah yes thats correct.

It would be best to add this to constructMainQueueContext() and remove the one in the initializer as apposed to just adding this again in the persistent stores didSet.

i.e.

private func constructMainQueueContext() -> NSManagedObjectContext {
    var managedObjectContext: NSManagedObjectContext!
    let setup: () -> Void = {
        managedObjectContext = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType)
        managedObjectContext.mergePolicy = NSMergePolicy(mergeType: .MergeByPropertyStoreTrumpMergePolicyType)
        managedObjectContext.parentContext = self.privateQueueContext

        NSNotificationCenter.defaultCenter().addObserver(self,
            selector: "stackMemberContextDidSaveNotification:",
            name: NSManagedObjectContextDidSaveNotification,
            object: managedObjectContext)
    }

    ...

    return managedObjectContext
}

The testPersistentStoreReset() test could also benefit from being adapted to wait for an observation of the private queue context being saved so we can ensure this case is under test. This is done in the SaveTests testBackgroundInsertAndSavePropagatesChanges

If you're interested in making these changes that would be great! Otherwise, we'll get right on it.

Thanks

[jimabc]

Great, I'll make the requisite changes. Thanks!

[rcedwards]

👍 Looks good. Thanks for the contribution!