refactoring-2.kt

class ViewModel {
    //... here comes the attributes and the model
    //we are changing (irrelevant for the example)
    
    fun addLikeLocally() {
        liked = true
        count++
    }
    
    fun removeLikeLocally() {
        liked = false
        count--
    }
}


//this is our class

fun onClickLikeButton() {
    if (viewModel.liked) {
        removeLike()
    } else {
        addLike()
    }
}


private fun addLike() {
    
    viewModel.addLikeLocally()
    
    //Then we call the API to update it on the server
    apiService.addLike.enqueue({ response -> 

        viewModel.count = response.count

    }, { failure ->

        //If any error occurs we should let the user know and go back to the previous state
        Toast.makeToast(activity, "Ops, an error occurred", LENGTH_LONG).show() 

        viewModel.removeLikeLocally()
    })
}

private removeLike() {
    
    viewModel.removeLikeLocally()

    //Then we call the API to update it on the server
    apiService.removeLike.enqueue({ response -> 

        viewModel.count = response.count

    }, { failure ->

        //If any error occurs we should let the user know
        Toast.makeToast(activity, "Ops, an error occurred", LENGTH_LONG).show() 

        viewModel.addLikeLocally()
    })
}