Nick Kohrn
Reputation: 6049
Unit Tests for Core Data Stack with In-Memory Store Keep Failing
I am building a personal project to allow my wife and I to monitor our grocery spending habits. The application utilizes Core Data, and I am having difficulty with my unit tests. I am testing my CoreDataStack class to ensure that its methods are saving and deleting objects.
Here is CoreDataStack:
internal class CoreDataStack {
// MARK: - Properties
private let modelName: String
internal lazy var storeContainer: NSPersistentContainer = {
let container = NSPersistentContainer(name: self.modelName)
container.loadPersistentStores { (storeDescription, error) in
if let error = error as NSError? {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
}
return container
}()
internal lazy var managedContext: NSManagedObjectContext = {
return self.storeContainer.viewContext
}()
// MARK: - Initialization
internal init(modelName: String = "Cart") {
self.modelName = modelName
}
// MARK: - Saving
internal func saveContext() {
guard managedContext.hasChanges else {
return
}
do {
try managedContext.save()
} catch let error as NSError {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
}
// MARK: - Deleting
internal func delete(object: NSManagedObject, from context: NSManagedObjectContext) {
context.delete(object)
}
internal func delete(allObjectsForEntity entity: String, from context: NSManagedObjectContext) {
let deleteFetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: entity)
let batchDeleteRequest = NSBatchDeleteRequest(fetchRequest: deleteFetchRequest)
do {
try storeContainer.persistentStoreCoordinator.execute(batchDeleteRequest, with: context)
} catch let error as NSError {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
}
}
I have created a subclass of CoreDataStack, called TestCoreDataStack, in my tests target. TestCoreDataStack uses an in-memory store so that it is destroyed when the encompassing test is finished.
Here is TestCoreDataStack:
internal final class TestCoreDataStack: CoreDataStack {
// MARK: - Initialization
internal override init(modelName: String = "Cart") {
super.init(modelName: modelName)
let persistentStoreDescription = NSPersistentStoreDescription()
persistentStoreDescription.type = NSInMemoryStoreType
let container = NSPersistentContainer(name: modelName)
container.persistentStoreDescriptions = [persistentStoreDescription]
container.loadPersistentStores { (storeDescription, error) in
if let error = error as NSError? {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
}
self.storeContainer = container
}
}
I also have a helper class, ManagedObjectFetcher, which is included only in my tests target, simply for fetching managed objects after they are saved or deleted. This class is used so that I can verify the counts and that the correct information exists after objects have been saved or deleted.
Hers is ManagedObjectFetcher:
internal final class ManagedObjectFetcher {
// MARK: - Properties
private let coreDataStack: CoreDataStack
// MARK: - Initialization
internal init(coreDataStack: CoreDataStack) {
self.coreDataStack = coreDataStack
}
// MARK: - All Records
internal func allRecords<T: NSManagedObject>(for entity : T.Type) -> [T] {
let request = T.fetchRequest()
do {
guard let results = try coreDataStack.managedContext.fetch(request) as? [T] else {
fatalError("Invalid results")
}
return results
} catch {
fatalError("Error with request: \(error)")
}
}
}
CoreDataStackTests is my XCTestCase subclass for testing CoreDataStack to ensure that objects are saved or deleted.
Here is CoreDataStackTests:
internal final class CoreDataStackTests: XCTestCase {
// MARK: - Properties
private var coreDataStack: TestCoreDataStack!
private var managedObjectFetcher: ManagedObjectFetcher!
// MARK: - Test Lifecycle
override func setUp() {
super.setUp()
coreDataStack = TestCoreDataStack()
managedObjectFetcher = ManagedObjectFetcher(coreDataStack: coreDataStack)
}
override func tearDown() {
coreDataStack = nil
managedObjectFetcher = nil
super.tearDown()
}
// MARK: - Saving
// Test 1
internal func test_CoreDataStack_Saves_GroceryItem() {
let preResults = managedObjectFetcher.allRecords(for: GroceryItem.self)
XCTAssertEqual(preResults.count, 0, "Expected `0`")
let _ = GroceryItem(name: "Name", singleItemPrice: Decimal(0.99), quantity: 1, date: Date(), isTaxable: true, managedObjectContext: coreDataStack.managedContext)
coreDataStack.saveContext()
let postResults = managedObjectFetcher.allRecords(for: GroceryItem.self)
XCTAssertEqual(postResults.count, 1, "Expected `1`")
}
// MARK: - Deleting
// Test 2
internal func test_CoreDataStack_Deletes_GroceryItem() {
let initialResults = managedObjectFetcher.allRecords(for: GroceryItem.self)
XCTAssertEqual(initialResults.count, 0, "Expected `0`")
let item = GroceryItem(name: "Name", singleItemPrice: Decimal(0.99), quantity: 1, date: Date(), isTaxable: true, managedObjectContext: coreDataStack.managedContext)
coreDataStack.saveContext()
let preResults = managedObjectFetcher.allRecords(for: GroceryItem.self)
XCTAssertEqual(preResults.count, 1, "Expected `1`")
coreDataStack.delete(object: item, from: coreDataStack.managedContext)
coreDataStack.saveContext()
let postResults = managedObjectFetcher.allRecords(for: GroceryItem.self)
XCTAssertEqual(postResults.count, 0, "Expected `0`")
}
// Test 3
internal func test_CoreDataStack_Deletes_AllGroceryItems() {
let initialResults = managedObjectFetcher.allRecords(for: GroceryItem.self)
XCTAssertEqual(initialResults.count, 0, "Expected `0`")
let _ = GroceryItem(name: "Name", singleItemPrice: Decimal(0.99), quantity: 1, date: Date(), isTaxable: true, managedObjectContext: coreDataStack.managedContext)
let _ = GroceryItem(name: "Another Name", singleItemPrice: Decimal(5.99), quantity: 2, date: Date(), isTaxable: false, managedObjectContext: coreDataStack.managedContext)
coreDataStack.saveContext()
let preResults = managedObjectFetcher.allRecords(for: GroceryItem.self)
XCTAssertEqual(preResults.count, 2, "Expected `2`")
coreDataStack.delete(allObjectsForEntity: GroceryItem.description(), from: coreDataStack.managedContext)
coreDataStack.saveContext()
let postResults = managedObjectFetcher.allRecords(for: GroceryItem.self)
XCTAssertEqual(postResults.count, 0, "Expected `0`")
}
}
When executing the tests in CoreDataStackTests, I run into the following issues that I can't resolve:
- Test 1: The test passes when ran alone. When all tests of
CoreDataStacktests are ran, it passes or fails. - Test 2: The test passes when ran alone. When all tests of
CoreDataStacktests are ran, it passes or fails. - Test 3: The test never passes whether it has ran alone or with the other tests. A Test Failure Breakpoint gets hit at
try storeContainer.persistentStoreCoordinator.execute(batchDeleteRequest, with: context)inside thedelete(allObjectsForEntity entity: String, from context: NSManagedObjectContext)method ofCoreDataStackwith each run.
This is the console output that I get after running all three tests:
Test Suite 'Selected tests' started at 2017-07-03 21:24:01.609
Test Suite 'CartTests.xctest' started at 2017-07-03 21:24:01.610
Test Suite 'CoreDataStackTests' started at 2017-07-03 21:24:01.610
Test Case '-[CartTests.CoreDataStackTests test_CoreDataStack_Deletes_AllGroceryItems]' started.
<unknown>:0: error: -[CartTests.CoreDataStackTests test_CoreDataStack_Deletes_AllGroceryItems] : failed: caught "NSInternalInconsistencyException", "Unknown command type <NSBatchDeleteRequest : resultType : 0, fetch :<NSFetchRequest: 0x6000000de450> (entity: GroceryItem; predicate: ((null)); sortDescriptors: ((null)); type: NSManagedObjectIDResultType; includesPropertyValues: NO; includesPendingChanges: NO; ) >"
(
0 CoreFoundation 0x000000010c90079b __exceptionPreprocess + 171
1 libobjc.A.dylib 0x000000010bd2e121 objc_exception_throw + 48
2 CoreData 0x000000010c34febf -[NSMappedObjectStore executeRequest:withContext:error:] + 303
3 CoreData 0x000000010c3f0f6d __65-[NSPersistentStoreCoordinator executeRequest:withContext:error:]_block_invoke + 2509
4 CoreData 0x000000010c3e9126 __55-[NSPersistentStoreCoordinator _routeHeavyweightBlock:]_block_invoke + 86
5 CoreData 0x000000010c3fcda9 gutsOfBlockToNSPersistentStoreCoordinatorPerform + 185
6 libdispatch.dylib 0x0000000110bfbbb9 _dispatch_client_callout + 8
7 libdispatch.dylib 0x0000000110c02500 _dispatch_queue_barrier_sync_invoke_and_complete + 92
8 CoreData 0x000000010c3e8ab5 _perform + 213
9 CoreData 0x000000010c3e8e3b -[NSPersistentStoreCoordinator _routeHeavyweightBlock:] + 283
10 CoreData 0x000000010c2f2aba -[NSPersistentStoreCoordinator executeRequest:withContext:error:] + 634
11 Cart 0x000000010b40b667 _T04Cart13CoreDataStackC16deleteAllObjectsySS9forEntity_So22NSManagedObjectContextC4fromtF + 391
12 CartTests 0x00000001240ea070 _T09CartTests013CoreDataStackB0C05test_cdE24_Deletes_AllGroceryItemsyyF + 3344
13 CartTests 0x00000001240eabc4 _T09CartTests013CoreDataStackB0C05test_cdE24_Deletes_AllGroceryItemsyyFTo + 36
14 CoreFoundation 0x000000010c884f8c __invoking___ + 140
15 CoreFoundation 0x000000010c884e60 -[NSInvocation invoke] + 320
16 XCTest 0x00000001224dd6e0 __24-[XCTestCase invokeTest]_block_invoke_2 + 451
17 XCTest 0x0000000122524bed -[XCUITestContext performInScope:] + 187
18 XCTest 0x00000001224dd4f8 -[XCTestCase invokeTest] + 254
19 XCTest 0x00000001224de424 __26-[XCTestCase performTest:]_block_invoke.362 + 42
20 XCTest 0x0000000122529432 +[XCTContext runInContextForTestCase:block:] + 163
21 XCTest 0x00000001224dddc0 -[XCTestCase performTest:] + 608
22 XCTest 0x00000001224da396 __27-[XCTestSuite performTest:]_block_invoke + 295
23 XCTest 0x00000001224d9f8d -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26
24 XCTest 0x00000001224da171 -[XCTestSuite performTest:] + 214
25 XCTest 0x00000001224da396 __27-[XCTestSuite performTest:]_block_invoke + 295
26 XCTest 0x00000001224d9f8d -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26
27 XCTest 0x00000001224da171 -[XCTestSuite performTest:] + 214
28 XCTest 0x00000001224da396 __27-[XCTestSuite performTest:]_block_invoke + 295
29 XCTest 0x00000001224d9f8d -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26
30 XCTest 0x00000001224da171 -[XCTestSuite performTest:] + 214
31 XCTest 0x0000000122530625 __44-[XCTTestRunSession runTestsAndReturnError:]_block_invoke + 40
32 XCTest 0x00000001224ecb99 -[XCTestObservationCenter _observeTestExecutionForBlock:] + 480
33 XCTest 0x00000001225304c4 -[XCTTestRunSession runTestsAndReturnError:] + 281
34 XCTest 0x00000001224c9d43 -[XCTestDriver runTestsAndReturnError:] + 254
35 XCTest 0x00000001225286b7 _XCTestMain + 616
36 CoreFoundation 0x000000010c8a3dcc __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
37 CoreFoundation 0x000000010c88833b __CFRunLoopDoBlocks + 203
38 CoreFoundation 0x000000010c887b34 __CFRunLoopRun + 1060
39 CoreFoundation 0x000000010c887499 CFRunLoopRunSpecific + 409
40 GraphicsServices 0x00000001121d79d7 GSEventRunModal + 62
41 UIKit 0x000000010cd7f0b8 UIApplicationMain + 159
42 Cart 0x000000010b40e637 main + 55
43 libdyld.dylib 0x0000000110c71771 start + 1
44 ??? 0x0000000000000005 0x0 + 5
)
Test Case '-[CartTests.CoreDataStackTests test_CoreDataStack_Deletes_AllGroceryItems]' failed (2636.006 seconds).
Test Case '-[CartTests.CoreDataStackTests test_CoreDataStack_Deletes_GroceryItem]' started.
<unknown>:0: error: -[CartTests.CoreDataStackTests test_CoreDataStack_Deletes_GroceryItem] : failed: caught "NSInvalidArgumentException", "executeFetchRequest:error: <null> is not a valid NSFetchRequest."
(
0 CoreFoundation 0x000000010c90079b __exceptionPreprocess + 171
1 libobjc.A.dylib 0x000000010bd2e121 objc_exception_throw + 48
2 CoreData 0x000000010c2f11d8 -[NSManagedObjectContext executeFetchRequest:error:] + 792
3 CartTests 0x00000001240eb1f7 _T09CartTests20ManagedObjectFetcherC10allRecordsSayxGxm3for_tSo09NSManagedD0CRbzlF + 247
4 CartTests 0x00000001240e7d86 _T09CartTests013CoreDataStackB0C05test_cdE20_Deletes_GroceryItemyyF + 182
5 CartTests 0x00000001240e9344 _T09CartTests013CoreDataStackB0C05test_cdE20_Deletes_GroceryItemyyFTo + 36
6 CoreFoundation 0x000000010c884f8c __invoking___ + 140
7 CoreFoundation 0x000000010c884e60 -[NSInvocation invoke] + 320
8 XCTest 0x00000001224dd6e0 __24-[XCTestCase invokeTest]_block_invoke_2 + 451
9 XCTest 0x0000000122524bed -[XCUITestContext performInScope:] + 187
10 XCTest 0x00000001224dd4f8 -[XCTestCase invokeTest] + 254
11 XCTest 0x00000001224de424 __26-[XCTestCase performTest:]_block_invoke.362 + 42
12 XCTest 0x0000000122529432 +[XCTContext runInContextForTestCase:block:] + 163
13 XCTest 0x00000001224dddc0 -[XCTestCase performTest:] + 608
14 XCTest 0x00000001224da396 __27-[XCTestSuite performTest:]_block_invoke + 295
15 XCTest 0x00000001224d9f8d -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26
16 XCTest 0x00000001224da171 -[XCTestSuite performTest:] + 214
17 XCTest 0x00000001224da396 __27-[XCTestSuite performTest:]_block_invoke + 295
18 XCTest 0x00000001224d9f8d -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26
19 XCTest 0x00000001224da171 -[XCTestSuite performTest:] + 214
20 XCTest 0x00000001224da396 __27-[XCTestSuite performTest:]_block_invoke + 295
21 XCTest 0x00000001224d9f8d -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26
22 XCTest 0x00000001224da171 -[XCTestSuite performTest:] + 214
23 XCTest 0x0000000122530625 __44-[XCTTestRunSession runTestsAndReturnError:]_block_invoke + 40
24 XCTest 0x00000001224ecb99 -[XCTestObservationCenter _observeTestExecutionForBlock:] + 480
25 XCTest 0x00000001225304c4 -[XCTTestRunSession runTestsAndReturnError:] + 281
26 XCTest 0x00000001224c9d43 -[XCTestDriver runTestsAndReturnError:] + 254
27 XCTest 0x00000001225286b7 _XCTestMain + 616
28 CoreFoundation 0x000000010c8a3dcc __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
29 CoreFoundation 0x000000010c88833b __CFRunLoopDoBlocks + 203
30 CoreFoundation 0x000000010c887b34 __CFRunLoopRun + 1060
31 CoreFoundation 0x000000010c887499 CFRunLoopRunSpecific + 409
32 GraphicsServices 0x00000001121d79d7 GSEventRunModal + 62
33 UIKit 0x000000010cd7f0b8 UIApplicationMain + 159
34 Cart 0x000000010b40e637 main + 55
35 libdyld.dylib 0x0000000110c71771 start + 1
36 ??? 0x0000000000000005 0x0 + 5
)
Test Case '-[CartTests.CoreDataStackTests test_CoreDataStack_Deletes_GroceryItem]' failed (11.969 seconds).
Test Case '-[CartTests.CoreDataStackTests test_CoreDataStack_Saves_GroceryItem]' started.
<unknown>:0: error: -[CartTests.CoreDataStackTests test_CoreDataStack_Saves_GroceryItem] : failed: caught "NSInvalidArgumentException", "executeFetchRequest:error: <null> is not a valid NSFetchRequest."
(
0 CoreFoundation 0x000000010c90079b __exceptionPreprocess + 171
1 libobjc.A.dylib 0x000000010bd2e121 objc_exception_throw + 48
2 CoreData 0x000000010c2f11d8 -[NSManagedObjectContext executeFetchRequest:error:] + 792
3 CartTests 0x00000001240eb1f7 _T09CartTests20ManagedObjectFetcherC10allRecordsSayxGxm3for_tSo09NSManagedD0CRbzlF + 247
4 CartTests 0x00000001240e6fe6 _T09CartTests013CoreDataStackB0C05test_cdE18_Saves_GroceryItemyyF + 182
5 CartTests 0x00000001240e7cb4 _T09CartTests013CoreDataStackB0C05test_cdE18_Saves_GroceryItemyyFTo + 36
6 CoreFoundation 0x000000010c884f8c __invoking___ + 140
7 CoreFoundation 0x000000010c884e60 -[NSInvocation invoke] + 320
8 XCTest 0x00000001224dd6e0 __24-[XCTestCase invokeTest]_block_invoke_2 + 451
9 XCTest 0x0000000122524bed -[XCUITestContext performInScope:] + 187
10 XCTest 0x00000001224dd4f8 -[XCTestCase invokeTest] + 254
11 XCTest 0x00000001224de424 __26-[XCTestCase performTest:]_block_invoke.362 + 42
12 XCTest 0x0000000122529432 +[XCTContext runInContextForTestCase:block:] + 163
13 XCTest 0x00000001224dddc0 -[XCTestCase performTest:] + 608
14 XCTest 0x00000001224da396 __27-[XCTestSuite performTest:]_block_invoke + 295
15 XCTest 0x00000001224d9f8d -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26
16 XCTest 0x00000001224da171 -[XCTestSuite performTest:] + 214
17 XCTest 0x00000001224da396 __27-[XCTestSuite performTest:]_block_invoke + 295
18 XCTest 0x00000001224d9f8d -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26
19 XCTest 0x00000001224da171 -[XCTestSuite performTest:] + 214
20 XCTest 0x00000001224da396 __27-[XCTestSuite performTest:]_block_invoke + 295
21 XCTest 0x00000001224d9f8d -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26
22 XCTest 0x00000001224da171 -[XCTestSuite performTest:] + 214
23 XCTest 0x0000000122530625 __44-[XCTTestRunSession runTestsAndReturnError:]_block_invoke + 40
24 XCTest 0x00000001224ecb99 -[XCTestObservationCenter _observeTestExecutionForBlock:] + 480
25 XCTest 0x00000001225304c4 -[XCTTestRunSession runTestsAndReturnError:] + 281
26 XCTest 0x00000001224c9d43 -[XCTestDriver runTestsAndReturnError:] + 254
27 XCTest 0x00000001225286b7 _XCTestMain + 616
28 CoreFoundation 0x000000010c8a3dcc __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
29 CoreFoundation 0x000000010c88833b __CFRunLoopDoBlocks + 203
30 CoreFoundation 0x000000010c887b34 __CFRunLoopRun + 1060
31 CoreFoundation 0x000000010c887499 CFRunLoopRunSpecific + 409
32 GraphicsServices 0x00000001121d79d7 GSEventRunModal + 62
33 UIKit 0x000000010cd7f0b8 UIApplicationMain + 159
34 Cart 0x000000010b40e637 main + 55
35 libdyld.dylib 0x0000000110c71771 start + 1
36 ??? 0x0000000000000005 0x0 + 5
)
Test Case '-[CartTests.CoreDataStackTests test_CoreDataStack_Saves_GroceryItem]' failed (4.826 seconds).
Test Suite 'CoreDataStackTests' failed at 2017-07-03 22:08:14.412.
Executed 3 tests, with 3 failures (3 unexpected) in 2652.801 (2652.802) seconds
Test Suite 'CartTests.xctest' failed at 2017-07-03 22:08:14.413.
Executed 3 tests, with 3 failures (3 unexpected) in 2652.801 (2652.803) seconds
Test Suite 'Selected tests' failed at 2017-07-03 22:08:14.413.
Executed 3 tests, with 3 failures (3 unexpected) in 2652.801 (2652.804) seconds
Test session log:
/var/folders/n9/48n8p_ms6rs2yc8vdkhq89br0000gn/T/com.apple.dt.XCTest/IDETestRunSession-44B21AFF-A887-42A9-8EF0-23B48DBC4744/CartTests-4BFEF3B5-D9B6-47D9-BA80-6007A7991D19/Session-CartTests-2017-07-03_212349-pZbWPl.log
What am I doing incorrectly that is causing these tests to fail?
Upvotes: 4
Views: 1788
Answers (1)
Cory Juhlin
Reputation: 384
Unfortunately, batch deletes are not supported with CoreData in-memory stores:
Important: Batch deletes are only available when you are using a SQLite persistent store.
Upvotes: 10
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