import UIKit

extension Container {

    var appDelegateAssembly: AppDelegateAssembly {
        if let stubClass = NSClassFromString("SharedShoppingAppTests.AppDelegateAssemblyStub") as? NSObject.Type,
            let stubInstance = stubClass.init() as? AppDelegateAssembly {
            return stubInstance
        }
        return Assembly(container: self)
    }

    private struct Assembly: AppDelegateAssembly {

        let container: Container

        // MAKR: AppDelegateAssembly

        var window: UIWindow {
            let window = UIWindow(frame: UIScreen.main.bounds)
            window.rootViewController = container.shoppingsViewController
            return window
        }

    }

}

import UIKit

extension Container {

    var appDelegateAssembly: AppDelegateAssembly {
        if let stubClass = NSClassFromString("SharedShoppingAppTests.AppDelegateAssemblyStub") as? NSObject.Type,
            let stubInstance = stubClass.init() as? AppDelegateAssembly {
            return stubInstance
        }
        return Assembly()
    }

    private struct Assembly: AppDelegateAssembly {

        var window: UIWindow {
            let window = UIWindow(frame: UIScreen.main.bounds)
            window.rootViewController = ViewController()
            return window
        }

    }

}

--- 
+++ 
@@ -7,14 +7,18 @@
             let stubInstance = stubClass.init() as? AppDelegateAssembly {
             return stubInstance
         }
-        return Assembly()
+        return Assembly(container: self)
     }
 
     private struct Assembly: AppDelegateAssembly {
 
+        let container: Container
+
+        // MAKR: AppDelegateAssembly
+
         var window: UIWindow {
             let window = UIWindow(frame: UIScreen.main.bounds)
-            window.rootViewController = ViewController()
+            window.rootViewController = container.shoppingsViewController
             return window
         }
 
Use ShoppingsViewController as a root for app window
