Testing fails to import sub dependency - @testable import SubModule - Use of undeclared type 'InternalSubModuleType'

Question

I have a unit test that needs to access internal methods/properties on a module imported by my application target.

E.g.

SubModule.swift

public class SubModuleType {
    ...
    internal let value: InternalSubModuleType
    ...
}

AppViewController.swift

import SubModule
// do things with SubModuleType

AppViewControllerTests.swift

@testable import App
@testable import SubModule

func testWithSubModule() {
    let internalSubModuleTypeInstance = SubModule.SubModuleType().value
    // ... run a test dependent on internalSubModuleTypeInstance
}

In this test I receive 'Use of undeclared type 'InternalSubModuleType'' when accessing .value.

• I have added the SubModule target to App-Tests "Target Dependencies"
• I have set "Enable Testability" to YES for both the App target and SubModule target for the scheme I'm compiling for testing.

@testable import is supposed to allow you to access types marked internal under these conditions. I'm not sure why I'd be receiving this compiler error. I can still use any type that is marked internal in my App target by using @testable but not my SubModule target.

Are you only allowed 1 target to be @testable import in a test target or is there something I'm missing?

---

using Xcode 9, Swift 3.2

Answer 1

Recreating the Testing target seemed to have done the trick for me.

Simply delete your old Testing target, create a new one and add this target to all the testing files that you have.