Deprecate usesStoreKit2IfAvailable

Sources/Misc/Deprecations.swift

@@ -14,7 +14,7 @@
 import Foundation
 import StoreKit
 
-// swiftlint:disable line_length missing_docs
+// swiftlint:disable line_length missing_docs file_length
 
 public extension Purchases {
 
@@ -389,3 +389,29 @@ extension CustomerInfo {
     }
 
 }
+
+public extension Configuration.Builder {
+
+    /// Set `usesStoreKit2IfAvailable`. If `true`, the SDK will use StoreKit 2 APIs internally. If disabled, it will use StoreKit 1 APIs instead.
+    /// - Parameter usesStoreKit2IfAvailable: enable StoreKit 2 on devices that support it.
+    /// Defaults to  `false`.
+    /// - Important: This configuration flag has been deprecated, and will be replaced by automatic remote configuration in the future.
+    /// However, apps using it should work correctly.
+    ///
+    @available(*, deprecated, message: """
+    RevenueCat currently uses StoreKit 1 for purchases, as its stability in production scenarios has
+    proven to be more performant than StoreKit 2.
+
+    We're collecting more data on the best approach, but StoreKit 1 vs StoreKit 2 is an implementation detail
+    that you shouldn't need to care about.
+
+    Simply remove this method call to let RevenueCat decide for you which StoreKit implementation to use.
+    """)
+    @objc func with(usesStoreKit2IfAvailable: Bool) -> Configuration.Builder {
+        self.storeKit2Setting = .init(useStoreKit2IfAvailable: usesStoreKit2IfAvailable)
+        return self
+    }
+
+}
+
+// swiftlint:enable line_length missing_docs file_length

Sources/Purchasing/Configuration.swift

@@ -31,7 +31,6 @@ import Foundation
  *                                  .with(userDefaults: myUserDefaults)
  *                                  .with(networkTimeout: 15)
  *                                  .with(storeKit1Timeout: 15)
- *                                  .with(usesStoreKit2IfAvailable: true)
  *                                  .build()
  *  Purchases.configure(with: configuration)
  * ```
@@ -75,13 +74,15 @@ import Foundation
     /// The Builder for ```Configuration```.
     @objc(RCConfigurationBuilder) public class Builder: NSObject {
 
+        // made internal to access it in Deprecations.swift
+        var storeKit2Setting: StoreKit2Setting = .default
+
         private static let minimumTimeout: TimeInterval = 5
 
         private(set) var apiKey: String
         private(set) var appUserID: String?
         private(set) var observerMode: Bool = false
         private(set) var userDefaults: UserDefaults?
-        private(set) var storeKit2Setting: StoreKit2Setting = .default
         private(set) var dangerousSettings: DangerousSettings?
         private(set) var networkTimeout = Configuration.networkTimeoutDefault
         private(set) var storeKit1Timeout = Configuration.storeKitRequestTimeoutDefault
@@ -136,16 +137,6 @@ import Foundation
             return self
         }
 
-        /**
-         * Set `usesStoreKit2IfAvailable`.
-         * - Parameter usesStoreKit2IfAvailable: opt in using StoreKit 2 on devices that support it.
-         * Defaults to  `false`.
-         */
-        @objc public func with(usesStoreKit2IfAvailable: Bool) -> Builder {
-            self.storeKit2Setting = .init(useStoreKit2IfAvailable: usesStoreKit2IfAvailable)
-            return self
-        }
-
         /**
          * Set `dangerousSettings`.
          * - Parameter dangerousSettings: Only use if suggested by RevenueCat support team.

Sources/Purchasing/Purchases/Purchases.swift

@@ -894,7 +894,6 @@ public extension Purchases {
      * ```swift
      *  Purchases.configure(
      *      with: Configuration.Builder(withAPIKey: Constants.apiKey)
-     *               .with(usesStoreKit2IfAvailable: true)
      *               .with(observerMode: false)
      *               .with(appUserID: "<app_user_id>")
      *               .build()
@@ -933,7 +932,6 @@ public extension Purchases {
      * ```swift
      *  Purchases.configure(
      *      with: .init(withAPIKey: Constants.apiKey)
-     *               .with(usesStoreKit2IfAvailable: true)
      *               .with(observerMode: false)
      *               .with(appUserID: "<app_user_id>")
      *      )

Tests/APITesters/SwiftAPITester/SwiftAPITester/ConfigurationAPI.swift

@@ -19,7 +19,6 @@ func checkConfigurationAPI() {
         .with(dangerousSettings: DangerousSettings())
         .with(networkTimeout: 1)
         .with(storeKit1Timeout: 1)
-        .with(usesStoreKit2IfAvailable: false)
         .with(platformInfo: Purchases.PlatformInfo(flavor: "", version: ""))
         .build()
     print(configuration)

Tests/UnitTests/Purchasing/Purchases/PurchasesConfiguringTests.swift

@@ -324,6 +324,7 @@ class PurchasesConfiguringTests: BasePurchasesTests {
         expect(self.storeKit1Wrapper.delegate) === self.purchasesOrchestrator
     }
 
+    @available(*, deprecated) // Ignore deprecation warnings
     func testSetsSelfAsStoreKit1WrapperDelegateForSK1() {
         let configurationBuilder = Configuration.Builder(withAPIKey: "")
             .with(usesStoreKit2IfAvailable: false)
@@ -332,6 +333,7 @@ class PurchasesConfiguringTests: BasePurchasesTests {
         expect(purchases.isStoreKit1Configured) == true
     }
 
+    @available(*, deprecated) // Ignore deprecation warnings
     func testDoesNotInitializeSK1IfSK2Enabled() throws {
         try AvailabilityChecks.iOS15APIAvailableOrSkipTest()