Different Assembly for Tests

I use Swift, CocoaPods and Typhoon for my project. I have some classes which provide me Webservice stuff. In my tests i want to use a different class which actually don't call the Webservice. So I thought it would be a good idea to just use another assembly for the test where i inject the fake webservice class.

@objc public protocol AuthService {
    func auth(username: String!, password:String!, onSuccess: (Token!) -> (Void), onError:(NSError!) -> (Void))
}

// "real" implementation
public class AuthServiceImpl: NSObject, AuthService {
    public func auth(username: String!, password:String!, onSuccess: (Token!) -> (Void), onError:(NSError!) -> (Void)){
       // do some webservice calls
    }
}

 // "fake" implementation
public class AuthServiceTestImpl: NSObject, AuthService {
    public func auth(username: String!, password:String!, onSuccess: (Token!) -> (Void), onError:(NSError!) -> (Void)){
       // do some file readings
    }
}

Pods File

platform :ios, '8.0'

target :Project, :exclusive => true do
   pod 'Typhoon', '~> 2.3.4'
end

The problem is that i get "Use of undeclared type 'TyphoonAssembly'" in my Assembly for the tests. Is there are Best Practice how to inject something else in test with typhoon?

Solution

This is called Modularizing Assemblies and is outlined in the user guide here.

The key concepts are:

You define recipes to build instances in an assembly. Some of these instance may refer to objects defined in another assembly. For example our view controller that depends on a service client.
To refer to objects that will come from another assembly simply create a property of the type of that assembly. Eg TyphoonAssembly<MyProtocol> or MyAssemblyType*.
Typhoon always proxies references to collaborating assemblies. The concrete realization is provided at startup time. You can provide an alternative implementation of the protocol or a sub-class.

To bootstrap Typhoon for tests:

let applicationAssembly = ApplicationAssembly()
let networkComponents = TestNetworkComponents()
TyphoonAssemblyActivator.withAssemblies([
    applicationAssembly, 
    networkComponents]).activate()

//This view controller will now be injected with test network components. 
let controller = assembly.viewController() as MyViewController

Good practice: If you wish to reuse the above assembly in several different test classes, create a method for that to avoid duplication.

Alternatively you may wish to patch a single component, which is outlined in the integration testing guide.