Recommendations for implementing a wrapper module

[mollyIV]

Hello,

A common practice is to separate third-party dependencies from production code via a dedicated module wrapper.

Typically, typealiases and function wrappers handle this well, but what about macros?

// Module A imports swift-navigation
// Module B imports Module A

// Module A hides swift-navigation implementation and provides wrapper functions, etc. 
// now, Module B wants to use a typealiased @CasePathable macro 

import ModuleA

@Caseable // A typealiased swift-case-paths @CasePathable macro from Module A to avoid relying on the 3rd-party implementation.
enum Destination {
  case one
}

It appears that the @CasePathable macro is implemented in a way that prevents us from using typealias with it.

One idea is to export the swift-case-paths module using @_exported:

// ModuleA

@_exported import CasePaths

Unfortunately, errors appear in Xcode 16, iOS 18.0:

External macro implementation type `CasePathsMacros.CasePathableMacro` could not be found for macro `CasePathable()`; No such file or directory

Can I ask for your recommendations on how to handle the issue described?

I’d be happy to prepare a small proof of concept (POC) if needed.

Thanks!

[mollyIV]

The errors are probably caused by custom configurations:

• Macro compilation issue in modularized project swift-composable-architecture#3292 (reply in thread)

I remember that custom Build Configurations could also interfere with macros. In SPM, "Debug" and "Release" are baked in, and the only available configurations. If your application target scheme uses custom build configurations (e.g, "Mock", "Staging", etc.) Xcode breaks and it displays the errors above. Previews don't work either.

Hey I just renamed my configuration as Debug / Release and all the macro errors disappeared.