Updated unit tests to tear down Core Data stack without warnings

Author: wibosco

CoreDataMigration-Example/CoreData/Model/CoreDataMigration_Example.xcdatamodeld/CoreDataMigration_Example 4.xcdatamodel/contents

@@ -7,8 +7,8 @@
     </entity>
     <entity name="Post" representedClassName="Post" syncable="YES" codeGenerationType="class">
         <attribute name="date" optional="YES" attributeType="Date" usesScalarValueType="NO" syncable="YES"/>
-        <attribute name="hidden" attributeType="Boolean" defaultValueString="NO" usesScalarValueType="YES" syncable="YES"/>
         <attribute name="postID" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="softDeleted" attributeType="Boolean" defaultValueString="NO" usesScalarValueType="YES" syncable="YES"/>
         <relationship name="body" maxCount="1" deletionRule="Nullify" destinationEntity="Content" syncable="YES"/>
         <relationship name="title" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="Content" syncable="YES"/>
     </entity>

CoreDataMigration-Example/ViewControllers/Posts/PostsViewController.swift

@@ -54,7 +54,7 @@ class PostsViewController: UITableViewController {
         let context = CoreDataManager.shared.mainContext
         let request = NSFetchRequest<Post>.init(entityName: "Post")
         let dateSort = NSSortDescriptor(key: "date", ascending: false)
-        let predicate = NSPredicate(format: "hidden == NO")
+        let predicate = NSPredicate(format: "softDeleted == NO")
 
         request.sortDescriptors = [dateSort]
         request.predicate = predicate

CoreDataMigration-Example/ViewControllers/Viewer/PostViewerViewController.swift

@@ -47,7 +47,7 @@ class PostViewerViewController: UIViewController {
                 request.predicate = NSPredicate(format: "postID == '\(self.viewModel.postID)'")
 
                 let post = try! context.fetch(request).first!
-                post.hidden = true
+                post.softDeleted = true
 
                 try? context.save()
 

CoreDataMigration-ExampleTests/Helpers/FileManager+Helper.swift

@@ -12,18 +12,11 @@ extension FileManager {
 
     // MARK: - Temp
 
-    static func clearTmpDirectoryContents() {
-        let tmpDirectoryContents = try! FileManager.default.contentsOfDirectory(atPath: NSTemporaryDirectory())
-        tmpDirectoryContents.forEach {
-            let fileURL = URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true).appendingPathComponent($0)
-            try! FileManager.default.removeItem(atPath: fileURL.path)
-        }
-    }
-    
-    static func moveFileFromBundleToTmpDirectory(fileName: String) -> URL {
-        let destinationURL = URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true).appendingPathComponent(fileName)
-        let bundleURL = Bundle(for: CoreDataMigratorTests.self).resourceURL!.appendingPathComponent(fileName)
-        try! FileManager.default.copyItem(at: bundleURL, to: destinationURL)
+    static func moveFileFromBundleToTempDirectory(filename: String) -> URL {
+        let destinationURL = URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true).appendingPathComponent(filename)
+        try? FileManager.default.removeItem(at: destinationURL)
+        let bundleURL = Bundle(for: CoreDataMigratorTests.self).resourceURL!.appendingPathComponent(filename)
+        try? FileManager.default.copyItem(at: bundleURL, to: destinationURL)
 
         return destinationURL
     }

CoreDataMigration-ExampleTests/Helpers/NSManagedObjectContext+Helper.swift

@@ -21,4 +21,13 @@ extension NSManagedObjectContext {
 
         self.persistentStoreCoordinator = persistentStoreCoordinator
     }
+    
+    // MARK: - Destroy
+    
+    func destroyStore() {
+        persistentStoreCoordinator?.persistentStores.forEach {
+            try? persistentStoreCoordinator?.remove($0)
+            try? persistentStoreCoordinator?.destroyPersistentStore(at: $0.url!, ofType: $0.type, options: nil)
+        }
+    }
 }

CoreDataMigration-ExampleTests/Tests/CoreData/Migration/CoreDataMigratorTests.swift

@@ -17,32 +17,28 @@ class CoreDataMigratorTests: XCTestCase {
 
     // MARK: - Lifecycle
 
-    override class func setUp() {
-        super.setUp()
-        
-        FileManager.clearTmpDirectoryContents()
-    }
-    
     override func setUp() {
         super.setUp()
 
         sut = CoreDataMigrator()
     }
 
     override func tearDown() {
-        FileManager.clearTmpDirectoryContents()
-        
         sut = nil
 
         super.tearDown()
     }
 
+    func tearDownCoreDataStack(context: NSManagedObjectContext) {
+        context.destroyStore()
+    }
+    
     // MARK: - Tests
 
     // MARK: SingleStepMigrations
 
     func test_individualStepMigration_1to2() {
-        let sourceURL = FileManager.moveFileFromBundleToTmpDirectory(fileName: "CoreDataMigration_Example_1.sqlite")
+        let sourceURL = FileManager.moveFileFromBundleToTempDirectory(filename: "CoreDataMigration_Example_1.sqlite")
         let toVersion = CoreDataMigrationVersion.version2
 
         sut.migrateStore(at: sourceURL, toVersion: toVersion)
@@ -70,10 +66,12 @@ class CoreDataMigratorTests: XCTestCase {
         XCTAssertEqual(migratedHexColor, "1BB732")
         XCTAssertEqual(migratedPostID, "FFFECB21-6645-4FDD-B8B0-B960D0E61F5A")
         XCTAssertEqual(migratedContent, "Test body")
+        
+        tearDownCoreDataStack(context: context)
     }
 
     func test_individualStepMigration_2to3() {
-        let sourceURL = FileManager.moveFileFromBundleToTmpDirectory(fileName: "CoreDataMigration_Example_2.sqlite")
+        let sourceURL = FileManager.moveFileFromBundleToTempDirectory(filename: "CoreDataMigration_Example_2.sqlite")
         let toVersion = CoreDataMigrationVersion.version3
 
         sut.migrateStore(at: sourceURL, toVersion: toVersion)
@@ -120,10 +118,12 @@ class CoreDataMigratorTests: XCTestCase {
         let migratedContents = try? context.fetch(contentRequest)
 
         XCTAssertEqual(migratedContents?.count, 20)
+        
+        tearDownCoreDataStack(context: context)
     }
 
     func test_individualStepMigration_3to4() {
-        let sourceURL = FileManager.moveFileFromBundleToTmpDirectory(fileName: "CoreDataMigration_Example_3.sqlite")
+        let sourceURL = FileManager.moveFileFromBundleToTempDirectory(filename: "CoreDataMigration_Example_3.sqlite")
         let toVersion = CoreDataMigrationVersion.version4
 
         sut.migrateStore(at: sourceURL, toVersion: toVersion)
@@ -145,13 +145,13 @@ class CoreDataMigratorTests: XCTestCase {
 
         let migratedDate = firstMigratedPost?.value(forKey: "date") as? Date
         let migratedPostID = firstMigratedPost?.value(forKey: "postID") as? String
-        let migratedHidden = firstMigratedPost?.value(forKey: "hidden") as? Bool
+        let migratedSoftDeleted = firstMigratedPost?.value(forKey: "softDeleted") as? Bool
         let migratedTitleContent = firstMigratedPost?.value(forKey: "title") as? NSManagedObject
         let migratedBodyContent = firstMigratedPost?.value(forKey: "body") as? NSManagedObject
 
         XCTAssertEqual(migratedDate?.timeIntervalSince1970, 1547494150.058821)
         XCTAssertEqual(migratedPostID, "FFFECB21-6645-4FDD-B8B0-B960D0E61F5A")
-        XCTAssertFalse(migratedHidden ?? true)
+        XCTAssertFalse(migratedSoftDeleted ?? true)
         XCTAssertNotNil(migratedTitleContent)
         XCTAssertNotNil(migratedBodyContent)
 
@@ -172,12 +172,14 @@ class CoreDataMigratorTests: XCTestCase {
         let migratedContents = try? context.fetch(contentRequest)
 
         XCTAssertEqual(migratedContents?.count, 20)
+        
+        tearDownCoreDataStack(context: context)
     }
 
     // MARK: MultipleStepMigrations
 
     func test_multipleStepMigration_fromVersion1toVersion4() {
-        let sourceURL = FileManager.moveFileFromBundleToTmpDirectory(fileName: "CoreDataMigration_Example_1.sqlite")
+        let sourceURL = FileManager.moveFileFromBundleToTempDirectory(filename: "CoreDataMigration_Example_1.sqlite")
         let toVersion = CoreDataMigrationVersion.version4
 
         sut.migrateStore(at: sourceURL, toVersion: toVersion)
@@ -195,20 +197,22 @@ class CoreDataMigratorTests: XCTestCase {
 
         XCTAssertEqual(migratedPosts?.count, 10)
         XCTAssertEqual(migratedColors?.count, 20)
+        
+        tearDownCoreDataStack(context: context)
     }
 
     // MARK: MigrationRequired
 
     func test_requiresMigration_fromVersion1ToCurrent_true() {
-        let storeURL = FileManager.moveFileFromBundleToTmpDirectory(fileName: "CoreDataMigration_Example_1.sqlite")
+        let storeURL = FileManager.moveFileFromBundleToTempDirectory(filename: "CoreDataMigration_Example_1.sqlite")
 
         let requiresMigration = sut.requiresMigration(at: storeURL, toVersion: CoreDataMigrationVersion.latest)
 
         XCTAssertTrue(requiresMigration)
     }
 
     func test_requiresMigration_fromVersion3ToVersion3_false() {
-        let storeURL = FileManager.moveFileFromBundleToTmpDirectory(fileName: "CoreDataMigration_Example_3.sqlite")
+        let storeURL = FileManager.moveFileFromBundleToTempDirectory(filename: "CoreDataMigration_Example_3.sqlite")
 
         let requiresMigration = sut.requiresMigration(at: storeURL, toVersion: .version3)