Swift cannot test core data in Xcode tests?

core-data, ios, swift

Solution

With Xcode 7, and `@testable`, you should no longer need to update the `managedObjectClassName` or use other hacks. Here's what I did to get it working in Xcode 7.2.

- Set your test target Host Application and check "Allow testing Host Applications APIs".

- Make sure none of your regular classes have a Target Membership pointing to the Test target. Only classes with unit test code should be set to the Test target.

- Add the `@testable` line to the top of all of your test classes:

import XCTest
@testable import MyApp

class MyAppTests: XCTestCase {
}

If you're still having issues you may want to try these additional tips: https://forums.developer.apple.com/message/28773#28949

I fought with this one for a while so I hope it helps someone else out.

Problem

I am working on a iOS project that uses core data. I am using swift. The Core Data stack is setup right and all seems to be fine. I have created a class for an entity (NSManagedObject) called TestEntity. The class looks like this: ``` import UIKit import CoreData class TestEntity: NSManagedObject { @NSManaged var name: NSString @NSManaged var age: NSNumber } ``` So, then I try to insert a new TestEntity in code using this line of code: ``` let te: TestEntity = NSEntityDescription.insertNewObjectForEntityForName("TestEntity", inManagedObjectContext: ctx) as TestEntity ``` I then get this error: I have seen some answers on stack overflow that say that I need to worry about the module name. So then I looked that up on the docs: https://developer.apple.com/library/content/documentation/Swift/Conceptual/BuildingCocoaApps/WritingSwiftClassesWithObjective-CBehavior.html Then I went in the core data entity for TestEntity and in the class field I entered myAppName.TestEntity When I run the app this line: ``` let te: TestEntity = NSEntityDescription.insertNewObjectForEntityForName("TestEntity", inManagedObjectContext: ctx) as TestEntity ``` still gives me the same error. What else could I be doing wrong? EDIT: So, I was able to make the app not crash anymore by changing the TestEntity NSManagedObject class to: import UIKit import CoreData ``` @objc(TestEntity) class TestEntity: NSManagedObject { @NSManaged var name: NSString @NSManaged var age: NSNumber } ``` So, I added the @objc(TestEntity) in it. This works with or without adding the appName before the TestEntity class name in the core data data model inspector. This works, but, when I run tests this line still crashes: ``` let te: TestEntity = NSEntityDescription.insertNewObjectForEntityForName("TestEntity", inManagedObjectContext: ctx) as TestEntity ``` So I found that this is an issue for other people: How to access Core Data generated Obj-C classes in test targets? How can we get core data to work in tests in swift. I am NOT using a bridging header in the app target and it all works great. The test target still crashes though. How can I fix the test target so it can run core data tests?

Original source