Insert an NSManagedObject into Swift with a single binding

Question

I am having trouble simply nesting an NSManagedObject with all relationships when using Swift on Xcode 6b3.

I put my play on GitHub , but the failed code (in the SwiftCoreDataRelationshipReproTests.swift testSwiftToOne unit test method) comes down to the following:

 let momURL : NSURL = NSBundle.mainBundle().URLForResource("SwiftCoreDataRelationshipRepro", withExtension: "momd") let mom : NSManagedObjectModel = NSManagedObjectModel(contentsOfURL: momURL) let psc : NSPersistentStoreCoordinator = NSPersistentStoreCoordinator(managedObjectModel: mom); let ps : NSPersistentStore = psc.addPersistentStoreWithType( NSInMemoryStoreType, configuration: nil, URL: nil, options: nil, error: nil) let moc : NSManagedObjectContext = NSManagedObjectContext() moc.persistentStoreCoordinator = psc // This throws an NSInvalidArgumentException: "An NSManagedObject of class 'NSManagedObject' must have a valid NSEntityDescription." NSManagedObject( entity: NSEntityDescription.entityForName("Pet", inManagedObjectContext: moc), insertIntoManagedObjectContext: moc) 

It seems like this should work. Nothing complicated.

My very similar Person object with many relationships can be inserted (and saved) correctly using Swift (as shown in testSwiftToMany ). A more complex version of Objective-C also successfully works with the same data model (test passing testObjcToOneAndToMany ).

Here is the exception:

 file:///%3Cunknown%3E: test failure: -[SwiftCoreDataRelationshipReproTests testSwiftToOne()] failed: failed: caught "NSInvalidArgumentException", "An NSManagedObject of class 'NSManagedObject' must have a valid NSEntityDescription." ( 0 CoreFoundation 0x00007fff8dd6525c __exceptionPreprocess + 172 1 libobjc.A.dylib 0x00007fff84ce5e75 objc_exception_throw + 43 2 CoreData 0x00007fff8765dd16 -[NSManagedObject initWithEntity:insertIntoManagedObjectContext:] + 550 3 SwiftCoreDataRelationshipReproTests 0x0000000100394d4a _TTOFCSo15NSManagedObjectcfMS_FT6entityGSQCSo19NSEntityDescription_30insertIntoManagedObjectContextGSQCSo22NSManagedObjectContext__S_ + 42 4 SwiftCoreDataRelationshipReproTests 0x00000001003946bd _TFCSo15NSManagedObjectCfMS_FT6entityGSQCSo19NSEntityDescription_30insertIntoManagedObjectContextGSQCSo22NSManagedObjectContext__S_ + 93 5 SwiftCoreDataRelationshipReproTests 0x0000000100393450 _TFC35SwiftCoreDataRelationshipReproTests35SwiftCoreDataRelationshipReproTests14testSwiftToOnefS0_FT_T_ + 816 6 SwiftCoreDataRelationshipReproTests 0x00000001003934c2 _TToFC35SwiftCoreDataRelationshipReproTests35SwiftCoreDataRelationshipReproTests14testSwiftToOnefS0_FT_T_ + 34 7 CoreFoundation 0x00007fff8dc50a5c __invoking___ + 140 8 CoreFoundation 0x00007fff8dc508c4 -[NSInvocation invoke] + 308 9 XCTest 0x00000001003b023a -[XCTestCase invokeTest] + 253 10 XCTest 0x00000001003b03ac -[XCTestCase performTest:] + 142 11 XCTest 0x00000001003b8ad0 -[XCTest run] + 257 12 XCTest 0x00000001003af68b -[XCTestSuite performTest:] + 379 13 XCTest 0x00000001003b8ad0 -[XCTest run] + 257 14 XCTest 0x00000001003af68b -[XCTestSuite performTest:] + 379 15 XCTest 0x00000001003b8ad0 -[XCTest run] + 257 16 XCTest 0x00000001003af68b -[XCTestSuite performTest:] + 379 17 XCTest 0x00000001003b8ad0 -[XCTest run] + 257 18 XCTest 0x00000001003acc8f __25-[XCTestDriver _runSuite]_block_invoke + 56 19 XCTest 0x00000001003b773d -[XCTestObservationCenter _observeTestExecutionForBlock:] + 162 20 XCTest 0x00000001003acbc8 -[XCTestDriver _runSuite] + 269 21 XCTest 0x00000001003ad34a -[XCTestDriver _checkForTestManager] + 551 22 XCTest 0x00000001003bb879 +[XCTestProbe runTests:] + 175 23 Foundation 0x00007fff8e0aacb7 __NSFireDelayedPerform + 333 24 CoreFoundation 0x00007fff8dccc494 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20 25 CoreFoundation 0x00007fff8dccbfcf __CFRunLoopDoTimer + 1151 26 CoreFoundation 0x00007fff8dd3d5aa __CFRunLoopDoTimers + 298 27 CoreFoundation 0x00007fff8dc87755 __CFRunLoopRun + 1525 28 CoreFoundation 0x00007fff8dc86f25 CFRunLoopRunSpecific + 309 29 HIToolbox 0x00007fff8e566a0d RunCurrentEventLoopInMode + 226 30 HIToolbox 0x00007fff8e566685 ReceiveNextEventCommon + 173 31 HIToolbox 0x00007fff8e5665bc _BlockUntilNextEventMatchingListInModeWithFilter + 65 32 AppKit 0x00007fff8538e26e _DPSNextEvent + 1434 33 AppKit 0x00007fff8538d8bb -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 122 34 AppKit 0x00007fff853819bc -[NSApplication run] + 553 35 AppKit 0x00007fff8536c7a3 NSApplicationMain + 940 36 SwiftCoreDataRelationshipRepro 0x000000010000ad55 top_level_code + 37 37 SwiftCoreDataRelationshipRepro 0x000000010000ad8a main + 42 38 libdyld.dylib 0x00007fff861115fd start + 1 ) 

Answer 1

Therefore, I could not solve the problem, but I think I narrowed it down to an error in the structure or Swift. Using entityForName equivalent to getting the object directly from the managedObjectModel, so I tried to do it like this:

 let entities = moc.persistentStoreCoordinator.managedObjectModel.entitiesByName; let keys = Array(entities.keys) let petVar : String = keys[1] as String let isEqual1 = (petVar == "Pet") // true let isEqual2 = (petVar.hashValue == "Pet".hashValue) // true let result1 = entities["Pet"] // nil let result2 = entities[petVar] // non-nil let result3 = entities.bridgeToObjectiveC().objectForKey("Pet".bridgeToObjectiveC()) // nil let result4 = entities.bridgeToObjectiveC().objectForKey(petVar.bridgeToObjectiveC()) // non-nil // Doesn't Pass XCTAssertNotNil(NSEntityDescription.entityForName("Pet", inManagedObjectContext: moc)); // Passes XCTAssertNotNil(NSEntityDescription.entityForName(petVar, inManagedObjectContext: moc)); 

It works with a key derived from the dictionary, but not with a string equivalent to the key (even the hash values ​​are the same).

I think this pretty definitely shows that there is an error either within the framework or in Swift itself. I am running Xcode (6b3) and 10.9.4

I think it's time for a bug report.