Add support for NSSecureCoding (#27)

Co-authored-by: Sindre Sorhus <sindresorhus@gmail.com>

Sources/Defaults/Defaults.swift

@@ -4,8 +4,15 @@ import Foundation
 public final class Defaults {
 	public class Keys {
 		public typealias Key = Defaults.Key
+
+		@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+		public typealias NSSecureCodingKey = Defaults.NSSecureCodingKey
+
 		public typealias OptionalKey = Defaults.OptionalKey
 
+		@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+		public typealias NSSecureCodingOptionalKey = Defaults.NSSecureCodingOptionalKey
+
 		fileprivate init() {}
 	}
 
@@ -31,6 +38,29 @@ public final class Defaults {
 		}
 	}
 
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public final class NSSecureCodingKey<T: NSSecureCoding>: Keys {
+		public let name: String
+		public let defaultValue: T
+		public let suite: UserDefaults
+
+		/// Create a defaults key.
+		public init(_ key: String, default defaultValue: T, suite: UserDefaults = .standard) {
+			self.name = key
+			self.defaultValue = defaultValue
+			self.suite = suite
+
+			super.init()
+
+			// Sets the default value in the actual UserDefaults, so it can be used in other contexts, like binding.
+			if UserDefaults.isNativelySupportedType(T.self) {
+				suite.register(defaults: [key: defaultValue])
+			} else if let value = try? NSKeyedArchiver.archivedData(withRootObject: defaultValue, requiringSecureCoding: true) {
+				suite.register(defaults: [key: value])
+			}
+		}
+	}
+
 	public final class OptionalKey<T: Codable>: Keys {
 		public let name: String
 		public let suite: UserDefaults
@@ -42,6 +72,18 @@ public final class Defaults {
 		}
 	}
 
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public final class NSSecureCodingOptionalKey<T: NSSecureCoding>: Keys {
+		public let name: String
+		public let suite: UserDefaults
+
+		/// Create an optional defaults key.
+		public init(_ key: String, suite: UserDefaults = .standard) {
+			self.name = key
+			self.suite = suite
+		}
+	}
+
 	fileprivate init() {}
 
 	/// Access a defaults value using a `Defaults.Key`.
@@ -52,6 +94,15 @@ public final class Defaults {
 		}
 	}
 
+	/// Access a defaults value using a `Defaults.NSSecureCodingKey`.
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public static subscript<T: NSSecureCoding>(key: NSSecureCodingKey<T>) -> T {
+		get { key.suite[key] }
+		set {
+			key.suite[key] = newValue
+		}
+	}
+
 	/// Access a defaults value using a `Defaults.OptionalKey`.
 	public static subscript<T: Codable>(key: OptionalKey<T>) -> T? {
 		get { key.suite[key] }
@@ -59,6 +110,15 @@ public final class Defaults {
 			key.suite[key] = newValue
 		}
 	}
+
+	/// Access a defaults value using a `Defaults.OptionalKey`.
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public static subscript<T: NSSecureCoding>(key: NSSecureCodingOptionalKey<T>) -> T? {
+		get { key.suite[key] }
+		set {
+			key.suite[key] = newValue
+		}
+	}
 	
 	/**
 	Reset the given keys back to their default values.
@@ -83,6 +143,17 @@ public final class Defaults {
 	public static func reset<T: Codable>(_ keys: Key<T>..., suite: UserDefaults = .standard) {
 		reset(keys, suite: suite)
 	}
+
+	/**
+	Reset the given keys back to their default values.
+
+	- Parameter keys: Keys to reset.
+	- Parameter suite: `UserDefaults` suite.
+	*/
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public static func reset<T: NSSecureCoding>(_ keys: NSSecureCodingKey<T>..., suite: UserDefaults = .standard) {
+		reset(keys, suite: suite)
+	}
 	
 	/**
 	Reset the given array of keys back to their default values.
@@ -109,6 +180,19 @@ public final class Defaults {
 			key.suite[key] = key.defaultValue
 		}
 	}
+
+	/**
+	Reset the given array of keys back to their default values.
+
+	- Parameter keys: Keys to reset.
+	- Parameter suite: `UserDefaults` suite.
+	*/
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public static func reset<T: NSSecureCoding>(_ keys: [NSSecureCodingKey<T>], suite: UserDefaults = .standard) {
+		for key in keys {
+			key.suite[key] = key.defaultValue
+		}
+	}
 	
 	/**
 	Reset the given optional keys back to `nil`.
@@ -132,6 +216,18 @@ public final class Defaults {
 	public static func reset<T: Codable>(_ keys: OptionalKey<T>..., suite: UserDefaults = .standard) {
 		reset(keys, suite: suite)
 	}
+
+	/**
+	Reset the given optional keys back to `nil`.
+
+	- Parameter keys: Keys to reset.
+	- Parameter suite: `UserDefaults` suite.
+	```
+	*/
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public static func reset<T: NSSecureCoding>(_ keys: NSSecureCodingOptionalKey<T>..., suite: UserDefaults = .standard) {
+		reset(keys, suite: suite)
+	}
 	
 	/**
 	Reset the given array of optional keys back to `nil`.
@@ -158,6 +254,19 @@ public final class Defaults {
 		}
 	}
 
+	/**
+	Reset the given array of optional keys back to `nil`.
+
+	- Parameter keys: Keys to reset.
+	- Parameter suite: `UserDefaults` suite.
+	*/
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public static func reset<T: NSSecureCoding>(_ keys: [NSSecureCodingOptionalKey<T>], suite: UserDefaults = .standard) {
+		for key in keys {
+			key.suite[key] = nil
+		}
+	}
+
 	/**
 	Remove all entries from the `UserDefaults` suite.
 	*/
@@ -190,6 +299,27 @@ extension UserDefaults {
 		return nil
 	}
 
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	private func _get<T: NSSecureCoding>(_ key: String) -> T? {
+		if UserDefaults.isNativelySupportedType(T.self) {
+			return object(forKey: key) as? T
+		}
+
+		guard
+			let data = data(forKey: key)
+		else {
+			return nil
+		}
+
+		do {
+			return try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as? T
+		} catch {
+			print(error)
+		}
+
+		return nil
+	}
+
 	fileprivate func _encode<T: Codable>(_ value: T) -> String? {
 		do {
 			// Some codable values like URL and enum are encoded as a top-level
@@ -212,6 +342,16 @@ extension UserDefaults {
 		set(_encode(value), forKey: key)
 	}
 
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	private func _set<T: NSSecureCoding>(_ key: String, to value: T) {
+		if UserDefaults.isNativelySupportedType(T.self) {
+			set(value, forKey: key)
+			return
+		}
+
+		set(try? NSKeyedArchiver.archivedData(withRootObject: value, requiringSecureCoding: true), forKey: key)
+	}
+
 	public subscript<T: Codable>(key: Defaults.Key<T>) -> T {
 		get { _get(key.name) ?? key.defaultValue }
 		set {
@@ -219,6 +359,14 @@ extension UserDefaults {
 		}
 	}
 
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public subscript<T: NSSecureCoding>(key: Defaults.NSSecureCodingKey<T>) -> T {
+		get { _get(key.name) ?? key.defaultValue }
+		set {
+			_set(key.name, to: newValue)
+		}
+	}
+
 	public subscript<T: Codable>(key: Defaults.OptionalKey<T>) -> T? {
 		get { _get(key.name) }
 		set {
@@ -231,6 +379,19 @@ extension UserDefaults {
 		}
 	}
 
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public subscript<T: NSSecureCoding>(key: Defaults.NSSecureCodingOptionalKey<T>) -> T? {
+		get { _get(key.name) }
+		set {
+			guard let value = newValue else {
+				set(nil, forKey: key.name)
+				return
+			}
+
+			_set(key.name, to: value)
+		}
+	}
+
 	fileprivate static func isNativelySupportedType<T>(_ type: T.Type) -> Bool {
 		switch type {
 		case is Bool.Type,

Sources/Defaults/Observation.swift

@@ -43,6 +43,27 @@ extension Defaults {
 		return [T].init(jsonString: "\([value])")?.first
 	}
 
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	private static func deserialize<T: NSSecureCoding>(_ value: Any?, to type: T.Type) -> T? {
+		guard
+			let value = value,
+			!(value is NSNull)
+		else {
+			return nil
+		}
+
+		// This handles the case where the value was a plist value using `isNativelySupportedType`
+		if let value = value as? T {
+			return value
+		}
+
+		guard let dataValue = value as? Data else {
+			return nil
+		}
+
+		return try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(dataValue) as? T
+	}
+
 	fileprivate final class BaseChange {
 		fileprivate let kind: NSKeyValueChange
 		fileprivate let indexes: IndexSet?
@@ -75,6 +96,23 @@ extension Defaults {
 		}
 	}
 
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public struct NSSecureCodingKeyChange<T: NSSecureCoding> {
+		public let kind: NSKeyValueChange
+		public let indexes: IndexSet?
+		public let isPrior: Bool
+		public let newValue: T
+		public let oldValue: T
+
+		fileprivate init(change: BaseChange, defaultValue: T) {
+			self.kind = change.kind
+			self.indexes = change.indexes
+			self.isPrior = change.isPrior
+			self.oldValue = deserialize(change.oldValue, to: T.self) ?? defaultValue
+			self.newValue = deserialize(change.newValue, to: T.self) ?? defaultValue
+		}
+	}
+
 	public struct OptionalKeyChange<T: Codable> {
 		public let kind: NSKeyValueChange
 		public let indexes: IndexSet?
@@ -91,6 +129,23 @@ extension Defaults {
 		}
 	}
 
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public struct NSSecureCodingOptionalKeyChange<T: NSSecureCoding> {
+		public let kind: NSKeyValueChange
+		public let indexes: IndexSet?
+		public let isPrior: Bool
+		public let newValue: T?
+		public let oldValue: T?
+
+		fileprivate init(change: BaseChange) {
+			self.kind = change.kind
+			self.indexes = change.indexes
+			self.isPrior = change.isPrior
+			self.oldValue = deserialize(change.oldValue, to: T.self)
+			self.newValue = deserialize(change.newValue, to: T.self)
+		}
+	}
+
 	private final class UserDefaultsKeyObservation: NSObject, DefaultsObservation {
 		fileprivate typealias Callback = (BaseChange) -> Void
 
@@ -182,6 +237,24 @@ extension Defaults {
 		return observation
 	}
 
+	/**
+	Observe a defaults key.
+	*/
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public static func observe<T: NSSecureCoding>(
+		_ key: Defaults.NSSecureCodingKey<T>,
+		options: NSKeyValueObservingOptions = [.initial, .old, .new],
+		handler: @escaping (NSSecureCodingKeyChange<T>) -> Void
+	) -> DefaultsObservation {
+		let observation = UserDefaultsKeyObservation(object: key.suite, key: key.name) { change in
+			handler(
+				NSSecureCodingKeyChange<T>(change: change, defaultValue: key.defaultValue)
+			)
+		}
+		observation.start(options: options)
+		return observation
+	}
+
 	/**
 	Observe an optional defaults key.
 
@@ -209,4 +282,22 @@ extension Defaults {
 		observation.start(options: options)
 		return observation
 	}
+
+	/**
+	Observe an optional defaults key.
+	*/
+	@available(iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+	public static func observe<T: NSSecureCoding>(
+		_ key: Defaults.NSSecureCodingOptionalKey<T>,
+		options: NSKeyValueObservingOptions = [.initial, .old, .new],
+		handler: @escaping (NSSecureCodingOptionalKeyChange<T>) -> Void
+	) -> DefaultsObservation {
+		let observation = UserDefaultsKeyObservation(object: key.suite, key: key.name) { change in
+			handler(
+				NSSecureCodingOptionalKeyChange<T>(change: change)
+			)
+		}
+		observation.start(options: options)
+		return observation
+	}
 }

Tests/DefaultsTests/DefaultsTests.swift

@@ -1,6 +1,7 @@
 import Foundation
 import XCTest
 import Defaults
+import CoreData
 
 let fixtureURL = URL(string: "https://sindresorhus.com")!
 let fixtureURL2 = URL(string: "https://example.com")!
@@ -13,12 +14,42 @@ enum FixtureEnum: String, Codable {
 
 let fixtureDate = Date()
 
+@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, *)
+final class ExamplePersistentHistory: NSPersistentHistoryToken {
+
+	let value: String
+
+	init(value: String) {
+		self.value = value
+		super.init()
+	}
+
+	required init?(coder: NSCoder) {
+		self.value = coder.decodeObject(forKey: "value") as! String
+		super.init()
+	}
+
+	override func encode(with coder: NSCoder) {
+		coder.encode(value, forKey: "value")
+	}
+
+	override class var supportsSecureCoding: Bool {
+		return true
+	}
+}
+
 extension Defaults.Keys {
 	static let key = Key<Bool>("key", default: false)
 	static let url = Key<URL>("url", default: fixtureURL)
 	static let `enum` = Key<FixtureEnum>("enum", default: .oneHour)
 	static let data = Key<Data>("data", default: Data([]))
 	static let date = Key<Date>("date", default: fixtureDate)
+
+	// NSSecureCoding
+	@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, *)
+	static let persistentHistoryValue = ExamplePersistentHistory(value: "ExampleToken")
+	@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, *)
+	static let persistentHistory = NSSecureCodingKey<ExamplePersistentHistory>("persistentHistory", default: persistentHistoryValue)
 }
 
 final class DefaultsTests: XCTestCase {
@@ -75,6 +106,14 @@ final class DefaultsTests: XCTestCase {
 		XCTAssertTrue(Defaults[.key])
 	}
 
+	@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, *)
+	func testNSSecureCodingKeys() {
+		XCTAssertEqual(Defaults.Keys.persistentHistoryValue.value, Defaults[.persistentHistory].value)
+		let newPersistentHistory = ExamplePersistentHistory(value: "NewValue")
+		Defaults[.persistentHistory] = newPersistentHistory
+		XCTAssertEqual(newPersistentHistory.value, Defaults[.persistentHistory].value)
+	}
+
 	func testUrlType() {
 		XCTAssertEqual(Defaults[.url], fixtureURL)
 
@@ -143,6 +182,24 @@ final class DefaultsTests: XCTestCase {
 		waitForExpectations(timeout: 10)
 	}
 
+	@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, *)
+	func testObserveNSSecureCodingKey() {
+		let key = Defaults.NSSecureCodingKey<ExamplePersistentHistory>("observeNSSecureCodingKey", default: ExamplePersistentHistory(value: "TestValue"))
+		let expect = expectation(description: "Observation closure being called")
+
+		var observation: DefaultsObservation!
+		observation = Defaults.observe(key, options: [.old, .new]) { change in
+			XCTAssertEqual(change.oldValue.value, "TestValue")
+			XCTAssertEqual(change.newValue.value, "NewTestValue")
+			observation.invalidate()
+			expect.fulfill()
+		}
+
+		Defaults[key] = ExamplePersistentHistory(value: "NewTestValue")
+
+		waitForExpectations(timeout: 10)
+	}
+
 	func testObserveOptionalKey() {
 		let key = Defaults.OptionalKey<Bool>("observeOptionalKey")
 		let expect = expectation(description: "Observation closure being called")
@@ -160,6 +217,24 @@ final class DefaultsTests: XCTestCase {
 		waitForExpectations(timeout: 10)
 	}
 
+	@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, *)
+	func testObserveNSSecureCodingOptionalKey() {
+		let key = Defaults.NSSecureCodingOptionalKey<ExamplePersistentHistory>("observeNSSecureCodingOptionalKey")
+		let expect = expectation(description: "Observation closure being called")
+
+		var observation: DefaultsObservation!
+		observation = Defaults.observe(key, options: [.old, .new]) { change in
+			XCTAssertNil(change.oldValue)
+			XCTAssertEqual(change.newValue?.value, "NewOptionalValue")
+			observation.invalidate()
+			expect.fulfill()
+		}
+
+		Defaults[key] = ExamplePersistentHistory(value: "NewOptionalValue")
+
+		waitForExpectations(timeout: 10)
+	}
+
 	func testObserveKeyURL() {
 		let fixtureURL = URL(string: "https://sindresorhus.com")!
 		let fixtureURL2 = URL(string: "https://example.com")!
@@ -199,8 +274,10 @@ final class DefaultsTests: XCTestCase {
 	func testResetKey() {
 		let defaultString1 = "foo1"
 		let defaultString2 = "foo2"
+		let defaultString3 = "foo3"
 		let newString1 = "bar1"
 		let newString2 = "bar2"
+		let newString3 = "bar3"
 		let key1 = Defaults.Key<String>("key1", default: defaultString1)
 		let key2 = Defaults.Key<String>("key2", default: defaultString2)
 		Defaults[key1] = newString1
@@ -208,6 +285,14 @@ final class DefaultsTests: XCTestCase {
 		Defaults.reset(key1)
 		XCTAssertEqual(Defaults[key1], defaultString1)
 		XCTAssertEqual(Defaults[key2], newString2)
+
+		if #available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, *) {
+			let key3 = Defaults.NSSecureCodingKey<ExamplePersistentHistory>("key3", default: ExamplePersistentHistory(value: defaultString3))
+			Defaults[key3] = ExamplePersistentHistory(value: newString3)
+			Defaults.reset(key3)
+
+			XCTAssertEqual(Defaults[key3].value, defaultString3)
+		}
 	}
 	
 	func testResetKeyArray() {
@@ -232,6 +317,7 @@ final class DefaultsTests: XCTestCase {
 	func testResetOptionalKey() {
 		let newString1 = "bar1"
 		let newString2 = "bar2"
+		let newString3 = "bar3"
 		let key1 = Defaults.OptionalKey<String>("optionalKey1")
 		let key2 = Defaults.OptionalKey<String>("optionalKey2")
 		Defaults[key1] = newString1
@@ -239,6 +325,13 @@ final class DefaultsTests: XCTestCase {
 		Defaults.reset(key1)
 		XCTAssertEqual(Defaults[key1], nil)
 		XCTAssertEqual(Defaults[key2], newString2)
+
+		if #available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, *) {
+			let key3 = Defaults.NSSecureCodingOptionalKey<ExamplePersistentHistory>("optionalKey3")
+			Defaults[key3] = ExamplePersistentHistory(value: newString3)
+			Defaults.reset(key3)
+			XCTAssertEqual(Defaults[key3], nil)
+		}
 	}
 	
 	func testResetOptionalKeyArray() {

readme.md

@@ -9,6 +9,7 @@ This package is used in production by apps like [Gifski](https://github.com/sind
 
 - **Strongly typed:** You declare the type and default value upfront.
 - **Codable support:** You can store any [Codable](https://developer.apple.com/documentation/swift/codable) value, like an enum.
+- **NSSecureCoding support:** You can store any [NSSecureCoding](https://developer.apple.com/documentation/foundation/nssecurecoding) value.
 - **Debuggable:** The data is stored as JSON-serialized values.
 - **Observation:** Observe changes to keys.
 - **Lightweight:** It's only ~300 lines of code.
@@ -88,6 +89,28 @@ if let name = Defaults[.name] {
 
 The default value is then `nil`.
 
+---
+
+If you have `NSSecureCoding` classes which you want to save, you can use them as follows:
+
+```swift
+extension Defaults.Keys {
+	static let someSecureCoding = NSSecureCodingKey<SomeNSSecureCodingClass>("someSecureCoding", default: SomeNSSecureCodingClass(string: "Default", int: 5, bool: true))
+	static let someOptionalSecureCoding = NSSecureCodingOptionalKey<Double>("someOptionalSecureCoding")
+}
+
+Defaults[.someSecureCoding].string
+//=> "Default"
+
+Defaults[.someSecureCoding].int
+//=> 5
+
+Defaults[.someSecureCoding].bool
+//=> true
+```
+
+You can use those keys just like in all the other examples. The return value will be your `NSSecureCoding` class.
+
 ### Enum example
 
 ```swift
@@ -248,6 +271,18 @@ Create a key with a default value.
 
 The default value is written to the actual `UserDefaults` and can be used elsewhere. For example, with a Interface Builder binding.
 
+#### `Defaults.NSSecureCodingKey` *(alias `Defaults.Keys.NSSecureCodingKey`)*
+
+```swift
+Defaults.NSSecureCodingKey<T>(_ key: String, default: T, suite: UserDefaults = .standard)
+```
+
+Type: `class`
+
+Create a NSSecureCoding key with a default value.
+
+The default value is written to the actual `UserDefaults` and can be used elsewhere. For example, with a Interface Builder binding.
+
 #### `Defaults.OptionalKey` *(alias `Defaults.Keys.OptionalKey`)*
 
 ```swift
@@ -258,6 +293,16 @@ Type: `class`
 
 Create a key with an optional value.
 
+#### `Defaults.NSSecureCodingOptionalKey` *(alias `Defaults.Keys.NSSecureCodingOptionalKey`)*
+
+```swift
+Defaults.NSSecureCodingOptionalKey<T>(_ key: String, suite: UserDefaults = .standard)
+```
+
+Type: `class`
+
+Create a NSSecureCoding key with an optional value.
+
 #### `Defaults.reset`
 
 ```swift
@@ -265,6 +310,11 @@ Defaults.reset<T: Codable>(_ keys: Defaults.Key<T>..., suite: UserDefaults = .st
 Defaults.reset<T: Codable>(_ keys: [Defaults.Key<T>], suite: UserDefaults = .standard)
 Defaults.reset<T: Codable>(_ keys: Defaults.OptionalKey<T>..., suite: UserDefaults = .standard)
 Defaults.reset<T: Codable>(_ keys: [Defaults.OptionalKey<T>], suite: UserDefaults = .standard)
+
+Defaults.reset<T: Codable>(_ keys: Defaults.NSSecureCodingKey<T>..., suite: UserDefaults = .standard)
+Defaults.reset<T: Codable>(_ keys: [Defaults.NSSecureCodingKey<T>], suite: UserDefaults = .standard)
+Defaults.reset<T: Codable>(_ keys: Defaults.NSSecureCodingOptionalKey<T>..., suite: UserDefaults = .standard)
+Defaults.reset<T: Codable>(_ keys: [Defaults.NSSecureCodingOptionalKey<T>], suite: UserDefaults = .standard)
 ```
 
 Type: `func`
@@ -281,6 +331,14 @@ Defaults.observe<T: Codable>(
 ) -> DefaultsObservation
 ```
 
+```swift
+Defaults.observe<T: Codable>(
+	_ key: Defaults.NSSecureCodingKey<T>,
+	options: NSKeyValueObservingOptions = [.initial, .old, .new],
+	handler: @escaping (NSSecureCodingKeyChange<T>) -> Void
+) -> DefaultsObservation
+```
+
 ```swift
 Defaults.observe<T: Codable>(
 	_ key: Defaults.OptionalKey<T>,
@@ -289,6 +347,14 @@ Defaults.observe<T: Codable>(
 ) -> DefaultsObservation
 ```
 
+```swift
+Defaults.observe<T: Codable>(
+	_ key: Defaults.NSSecureCodingOptionalKey<T>,
+	options: NSKeyValueObservingOptions = [.initial, .old, .new],
+	handler: @escaping (NSSecureCodingOptionalKeyChange<T>) -> Void
+) -> DefaultsObservation
+```
+
 Type: `func`
 
 Observe changes to a key or an optional key.