Swift 2.0: Could not cast value MyApp.MyCustomClass to MyAppTests.MyCustomClass when using Set

问题

This is an error:

Could not cast value of type MyApp.Member (0x1674daf8) to MyAppTests.Member (0x4c07248).

You can reproduce a bug in easy way:

1. Setup two NSManagedObject

   @objc(Member)
   class Member: NSManagedObject {
       @NSManaged var family: Family
   }
   
   @objc(Family)
   class Family: NSManagedObject {
       @NSManaged var members: Set<Member>
   }
   

2. Setup this also in your .xcdatamodel:

3. Then in your TestFile:

   func testA() {
   
       let family = Family.MR_createEntityInContext(context)
       let father = Member.MR_createEntityInContext(context)
   
       father.family = family
   
       let firstMember = family.members.first
   
       XCTAssertEqual(firstMember!, father)
   }
   

回答1:

I have found a solution:

I suppose that those who has such problem, imported their files into test target this way:

Since they should do it just like this:

So, just remove the files from your test target. And then if you need your files within test target just use @testable keyword within your every test class.

This way there is no problem with casting values between targets anymore. It worked for me:-) Enjoy:-)

Read more from Swift 2 + Xcode 7: Unit Testing Access Made Easy!!!!

来源：https://stackoverflow.com/questions/31089389/swift-2-0-could-not-cast-value-myapp-mycustomclass-to-myapptests-mycustomclass