What are testing strategies for StoreKit 2 in Swift?

    // Example testing strategy for StoreKit 2 in Swift
    import StoreKit

    class InAppPurchaseManager {
        func fetchProducts(completion: @escaping ([Product]) -> Void) {
            Task {
                do {
                    let products = try await Product.products(for: ["com.example.app.product1", "com.example.app.product2"])
                    completion(products)
                } catch {
                    print("Error fetching products: \(error)")
                    completion([])
                }
            }
        }

        func purchase(product: Product) async {
            do {
                let result = try await product.purchase()
                switch result {
                case .success(let verificationResult):
                    // Handle successful purchase
                case .userCancelled:
                    // Handle user cancellation
                case .pending:
                    // Handle pending purchase
                }
            } catch {
                print("Purchase failed: \(error)")
            }
        }
    }