Errors should be decoupled from the backing storage

[sirioz]

Hi,

I think that error handling should be decoupled from the backing storage.
Now if I want to catch errors I need to reintroduce a dependancy to a Realm or CoreData.

Example:

do {
            try storage.mainContext?.add(user)
        } catch (let error) // this error depends on the backing storage module

[MarcoSantarossa]

Hi @sirioz,
You're perfectly right. In our TODO backlog, we have the task to add a common interface for the errors of both Realm and CoreData. At the moment, we are catching several errors internally but we don't expose because we have to define a common and clean interface to use for any kind of storage we are going to support. We didn't start to work on it yet and I'm not able to provide a date for this feature. Since you have shown us that it has a quite high priority, we are going to prioritize it and start working on it asap.

We can leave this issue open to keep track since I guess other people are interesting on it.

[MarcoSantarossa]

Issues fixed with #23. Thank you @sirioz for being our main contributor 😄