diff --git a/abtesting/ABTestingExample.xcodeproj/project.pbxproj b/abtesting/ABTestingExample.xcodeproj/project.pbxproj
index aafb770a5..883bdad80 100644
--- a/abtesting/ABTestingExample.xcodeproj/project.pbxproj
+++ b/abtesting/ABTestingExample.xcodeproj/project.pbxproj
@@ -193,17 +193,18 @@
 				TargetAttributes = {
 					10B92C9B202E3603008DBD68 = {
 						CreatedOnToolsVersion = 9.2;
+						LastSwiftMigration = 1010;
 						ProvisioningStyle = Automatic;
 						TestTargetID = 8DFFBF991F9E6C5200C3483E;
 					};
 					8DFFBF991F9E6C5200C3483E = {
 						CreatedOnToolsVersion = 8.3.3;
-						LastSwiftMigration = 0930;
+						LastSwiftMigration = 1010;
 						ProvisioningStyle = Automatic;
 					};
 					8DFFBFAD1F9E6C5200C3483E = {
 						CreatedOnToolsVersion = 8.3.3;
-						LastSwiftMigration = 0930;
+						LastSwiftMigration = 1010;
 						ProvisioningStyle = Automatic;
 						TestTargetID = 8DFFBF991F9E6C5200C3483E;
 					};
@@ -336,7 +337,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.firebase.ABTestingExample.ABTestingExampleUITests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				TEST_TARGET_NAME = ABTestingExample;
 			};
@@ -361,7 +362,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.firebase.ABTestingExample.ABTestingExampleUITests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				TEST_TARGET_NAME = ABTestingExample;
 			};
@@ -487,8 +488,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks $(PODS_CONFIGURATION_BUILD_DIR)/GoogleToolboxForMac $(PODS_CONFIGURATION_BUILD_DIR)/nanopb $(PODS_CONFIGURATION_BUILD_DIR)/Protobuf";
 				PRODUCT_BUNDLE_IDENTIFIER = com.firebase.ABTestingExample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 			};
 			name = Debug;
 		};
@@ -501,8 +501,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks $(PODS_CONFIGURATION_BUILD_DIR)/GoogleToolboxForMac $(PODS_CONFIGURATION_BUILD_DIR)/nanopb $(PODS_CONFIGURATION_BUILD_DIR)/Protobuf";
 				PRODUCT_BUNDLE_IDENTIFIER = com.firebase.ABTestingExample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 			};
 			name = Release;
 		};
@@ -515,8 +514,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.firebase.ABTestingExampleTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/ABTestingExample.app/ABTestingExample";
 			};
 			name = Debug;
@@ -530,8 +528,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.firebase.ABTestingExampleTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/ABTestingExample.app/ABTestingExample";
 			};
 			name = Release;
diff --git a/abtesting/ABTestingExample/AppDelegate.swift b/abtesting/ABTestingExample/AppDelegate.swift
index a452d0846..50368108e 100644
--- a/abtesting/ABTestingExample/AppDelegate.swift
+++ b/abtesting/ABTestingExample/AppDelegate.swift
@@ -22,7 +22,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
 
   var window: UIWindow?
 
-  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
+  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
     FirebaseApp.configure()
     return true
   }
diff --git a/abtesting/ABTestingExample/ViewController.swift b/abtesting/ABTestingExample/ViewController.swift
index a81b33f13..a6d5dccf2 100644
--- a/abtesting/ABTestingExample/ViewController.swift
+++ b/abtesting/ABTestingExample/ViewController.swift
@@ -87,8 +87,13 @@ class ViewController: UIViewController, UITableViewDataSource {
   }
 
   @objc func printInstanceIDToken() {
-    let instanceID = InstanceID.instanceID().token() ?? "null"
-    print("InstanceID token: \(instanceID)")
+    InstanceID.instanceID().instanceID { (result, error) in
+      if let error = error {
+        print("Error fetching InstanceID: \(error)")
+      } else if let result = result {
+        print("InstanceID token: \(result.token)")
+      }
+    }
   }
 
   deinit {
@@ -104,7 +109,7 @@ class ViewController: UIViewController, UITableViewDataSource {
       navigationController?.navigationBar.barTintColor = ViewController.lightColors.primary
       navigationController?.navigationBar.barStyle = .`default`
       navigationController?.navigationBar.titleTextAttributes = [
-        NSAttributedStringKey.foregroundColor: UIColor.black
+        NSAttributedString.Key.foregroundColor: UIColor.black
       ]
       tableView.separatorColor = .gray
       tableView.backgroundColor = UIColor(red: 0.94, green: 0.94, blue: 0.94, alpha: 1)
@@ -113,7 +118,7 @@ class ViewController: UIViewController, UITableViewDataSource {
       navigationController?.navigationBar.barTintColor = ViewController.darkColors.primary
       navigationController?.navigationBar.barStyle = .black
       navigationController?.navigationBar.titleTextAttributes = [
-        NSAttributedStringKey.foregroundColor: UIColor.white
+        NSAttributedString.Key.foregroundColor: UIColor.white
       ]
       tableView.separatorColor = .lightGray
       tableView.backgroundColor = ViewController.darkColors.secondary