Ensembles; Handling errors

[MickStupp]

I'd very much like to handle the error 'CDEErrorCode.cloudIdentityChange' as a run-time alert, but cannot get any line to work. Logic would suggest the following in the completion block:

  func sync(_ completion: (() -> Void)?) {
    if !ensemble.isLeeched {
        ensemble.leechPersistentStore {
            error in
            completion?()
        }        
    } else {
        //ensemble.merge
        ensemble.merge(completion: {
            error in
            if error == CDEErrorCode.cloudIdentityChanged {
                iCloudAlert()
            }
            completion?()  
        })
    }        
}

But the 'if error == ...' line returns the message, " Binary operator '==' cannot be applied to operands of type 'Error?' and 'CDEErrorCode' "

Have tried many variants & type casts to no avail. Suggestions would be hugely appreciated. PS This is Swift 3, with Ensembles v1.7.1. Everything works wonderfully, just can't catch this error specifically.

[drewmccormack]

Would think you just cast to CDEErrorCode.

if let cdeError = error as? CDEErrorCode, cdeError == .cloudIdentityChanged {
    iCloudAlert()
}

[MickStupp]

You make it sound so simple. Many thanks. I revisited various casts I tried and still can't see why they didn't work, so setting time aside today to get this figured out and properly understood.

[MickStupp]

For the benefit of anyone missing the point like I did: Comma separated conditions in a 'if' statement are not the same as && (which is where I went wrong in one of my many 'nearly there' attempts). In this example, cdeError will not be of type CDEErrorCode if the two conditions are anything but two separate conditions, comma separated! Thanks again to Drew for this idiots guide to Swift.

[drewmccormack]

There are similarities to &&, but indeed not the same. It evaluates each condition in turn, and will not proceed unless they are all true. That much is the same. But they are separate statements, and evaluated separately.

Effectively, you are doing this:

if let cdeError = error as? CDEErrorCode {
    if cdeError == .cloudIdentityChanges {
        ...