NSFetchRequest返回的AnyObject数组错误，“Swift动态转换失败”在XCTestCase中使用Swift XCode 6 Beta 4进行演示 [英] AnyObject array returned by NSFetchRequest errors with "Swift dynamic cast failed" upon cast in Swift XCode 6 Beta 4 in XCTestCase

问题描述

我知道此处之前已经询问过，但答案没有解决我的问题，我想发布我的完整测试用例。

I know this has been asked before here but the answer did not solve my problem, and I wanted to post my full test case.

我按照屏幕截图设置我的实体：
实体设置图像

I setup my Entities as in the screenshot: Entities setup image

我有XCode生成NSManagedObject的子类：

I had XCode generate a subclass of NSManagedObject:

import Foundation
import CoreData

class Goal: NSManagedObject {
    @NSManaged var displayDesc: String
    @NSManaged var motivation: String
    @NSManaged var cratedDate: NSDate
    @NSManaged var goalType: NSNumber
}

它还创建了一个名为LifeList-Bridging-Header.h的头文件，它是空的。

It also created a header file called LifeList-Bridging-Header.h that is empty.

最后我设置了一个测试用例：

Finally I setup a test case:

import UIKit
import XCTest
import CoreData

class CastExceptionTest: XCTestCase {
    var _managedObjectContext: NSManagedObjectContext? = nil
    var _persistentStoreCoordinator: NSPersistentStoreCoordinator? = nil
    var _managedObjectModel: NSManagedObjectModel? = nil

    var applicationDocumentsDirectory: NSURL {
        let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
        return urls[urls.count-1] as NSURL
    }

    var managedObjectContext: NSManagedObjectContext {
        if !_managedObjectContext {
            let coordinator = self.persistentStoreCoordinator
            if coordinator != nil {
                _managedObjectContext = NSManagedObjectContext()
                _managedObjectContext!.persistentStoreCoordinator = coordinator
            }
        }
        return _managedObjectContext!
    }

    var managedObjectModel: NSManagedObjectModel {
        if !_managedObjectModel {
            //The data model is just an Entity named Goal with 4 attributes one named displayDesc.
            let modelURL = NSBundle.mainBundle().URLForResource("LifeList", withExtension: "momd")
            _managedObjectModel = NSManagedObjectModel(contentsOfURL: modelURL)
        }
        return _managedObjectModel!
    }

    var persistentStoreCoordinator: NSPersistentStoreCoordinator {
        if !_persistentStoreCoordinator {
            let storeURL = self.applicationDocumentsDirectory.URLByAppendingPathComponent("CastExceptionTest.sqlite")
            var error: NSError? = nil
            _persistentStoreCoordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
            if _persistentStoreCoordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: storeURL, options: nil, error: &error) == nil {
                abort()
            }
        }
        return _persistentStoreCoordinator!
    }

    func testCase() {
        //Create and save a new Goal
        let entityDescription = NSEntityDescription.entityForName("Goal", inManagedObjectContext: managedObjectContext)
        let goal = Goal(entity: entityDescription, insertIntoManagedObjectContext: managedObjectContext)
        goal.displayDesc = "Test text"
        var error:NSError?
        managedObjectContext.save(&error)

        //Load the entities
        let fetch = NSFetchRequest(entityName: "Goal")
        let objectArray: [AnyObject]? = managedObjectContext.executeFetchRequest(fetch, error: &error)
        for object in objectArray! {
            let goal = object as Goal
            print(goal.displayDesc)
        }
    }
}

以下是运行测试的结果：

The following is the outcome of running the test:

libswift_stdlib_core.dylib`swift_dynamicCastClassUnconditional:
0x105b147c0:  pushq  %rbp
0x105b147c1:  movq   %rsp, %rbp
0x105b147c4:  pushq  %r14
0x105b147c6:  pushq  %rbx
0x105b147c7:  movq   %rsi, %rbx
0x105b147ca:  movq   %rdi, %r14
0x105b147cd:  testq  %r14, %r14
0x105b147d0:  je     0x105b147fe               ; swift_dynamicCastClassUnconditional + 62
0x105b147d2:  movabsq $-0x7fffffffffffffff, %rax
0x105b147dc:  andq   %r14, %rax
0x105b147df:  jne    0x105b147fe               ; swift_dynamicCastClassUnconditional + 62
0x105b147e1:  movq   %r14, %rdi
0x105b147e4:  callq  0x105b29764               ; symbol stub for: object_getClass
0x105b147e9:  nopl   (%rax)
0x105b147f0:  cmpq   %rbx, %rax
0x105b147f3:  je     0x105b1480d               ; swift_dynamicCastClassUnconditional + 77
0x105b147f5:  movq   0x8(%rax), %rax
0x105b147f9:  testq  %rax, %rax
0x105b147fc:  jne    0x105b147f0               ; swift_dynamicCastClassUnconditional + 48
0x105b147fe:  leaq   0x1da7d(%rip), %rax       ; "Swift dynamic cast failed"
0x105b14805:  movq   %rax, 0x88da4(%rip)       ; gCRAnnotations + 8
0x105b1480c:  int3   
0x105b1480d:  movq   %r14, %rax
0x105b14810:  popq   %rbx
0x105b14811:  popq   %r14
0x105b14813:  popq   %rbp
0x105b14814:  retq   
0x105b14815:  nopw   %cs:(%rax,%rax)

推荐答案

所有功劳归于jrtuton。有没有办法将答案归于他？

All credit goes to jrtuton for this. Is there some way to attribute the answer to him?

以下是所做的更改：

1. 从测试目标的编译列表中删除了Goal类。

1. Removed the Goal class from the compile list for the test target.

为Goal类添加了适当的访问修饰符：

Added proper access modifiers to the Goal class:

public class Goal: NSManagedObject {

    @NSManaged public var displayDesc: String
    @NSManaged public var motivation: String
    @NSManaged public var cratedDate: NSDate
    @NSManaged public var goalType: NSNumber

添加了一个公共init方法：

Added a public init method:

public init(entity: NSEntityDescription, insertIntoManagedObjectContext:   NSManagedObjectContext) {
    super.init(entity: entity, insertIntoManagedObjectContext:   insertIntoManagedObjectContext)
}

在我的测试类中导入LifeList模块：

Imported the LifeList module in my test class:

import LifeList

这篇关于NSFetchRequest返回的AnyObject数组错误，“Swift动态转换失败”在XCTestCase中使用Swift XCode 6 Beta 4进行演示的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！