Get rid of OptionalKey

.travis.yml

@@ -1,3 +1,3 @@
 language: swift
-osx_image: xcode11.3
+osx_image: xcode11.4
 script: xcodebuild test -project Defaults.xcodeproj -scheme Defaults-macOS

Defaults.podspec

@@ -8,7 +8,7 @@ Pod::Spec.new do |s|
 	s.authors = { 'Sindre Sorhus' => 'sindresorhus@gmail.com' }
 	s.source = { :git => 'https://github.com/sindresorhus/Defaults.git', :tag => "v#{s.version}" }
 	s.source_files = 'Sources/**/*.swift'
-	s.swift_version = '5.1'
+	s.swift_version = '5.2'
 	s.macos.deployment_target = '10.12'
 	s.ios.deployment_target = '10.0'
 	s.tvos.deployment_target = '10.0'

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.1
+// swift-tools-version:5.2
 import PackageDescription
 
 let package = Package(

Sources/Defaults/Defaults.swift

@@ -8,8 +8,6 @@ public final class Defaults {
 		@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
 		public typealias NSSecureCodingKey = Defaults.NSSecureCodingKey
 
-		public typealias OptionalKey = Defaults.OptionalKey
-
 		@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
 		public typealias NSSecureCodingOptionalKey = Defaults.NSSecureCodingOptionalKey
 
@@ -29,6 +27,10 @@ public final class Defaults {
 
 			super.init()
 
+			if (defaultValue as? _DefaultsOptionalType)?.isNil == true {
+				return
+			}
+
 			// Sets the default value in the actual UserDefaults, so it can be used in other contexts, like binding.
 			if UserDefaults.isNativelySupportedType(Value.self) {
 				suite.register(defaults: [key: defaultValue])
@@ -52,6 +54,10 @@ public final class Defaults {
 
 			super.init()
 
+			if (defaultValue as? _DefaultsOptionalType)?.isNil == true {
+				return
+			}
+
 			// Sets the default value in the actual UserDefaults, so it can be used in other contexts, like binding.
 			if UserDefaults.isNativelySupportedType(Value.self) {
 				suite.register(defaults: [key: defaultValue])
@@ -61,17 +67,6 @@ public final class Defaults {
 		}
 	}
 
-	public final class OptionalKey<Value: Codable>: 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
-		}
-	}
-
 	@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
 	public final class NSSecureCodingOptionalKey<Value: NSSecureCoding>: Keys {
 		public let name: String
@@ -103,15 +98,7 @@ public final class Defaults {
 		}
 	}
 
-	/// Access a defaults value using a `Defaults.OptionalKey`.
-	public static subscript<Value: Codable>(key: OptionalKey<Value>) -> Value? {
-		get { key.suite[key] }
-		set {
-			key.suite[key] = newValue
-		}
-	}
-
-	/// Access a defaults value using a `Defaults.OptionalKey`.
+	/// Access a defaults value using a `Defaults.NSSecureCodingOptionalKey`.
 	@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
 	public static subscript<Value: NSSecureCoding>(key: NSSecureCodingOptionalKey<Value>) -> Value? {
 		get { key.suite[key] }
@@ -193,29 +180,6 @@ public final class Defaults {
 			key.suite[key] = key.defaultValue
 		}
 	}
-
-	/**
-	Reset the given optional keys back to `nil`.
-
-	- Parameter keys: Keys to reset.
-	- Parameter suite: `UserDefaults` suite.
-
-	```
-	extension Defaults.Keys {
-		static let unicorn = OptionalKey<String>("unicorn")
-	}
-
-	Defaults[.unicorn] = "🦄"
-
-	Defaults.reset(.unicorn)
-
-	Defaults[.unicorn]
-	//=> nil
-	```
-	*/
-	public static func reset<Value: Codable>(_ keys: OptionalKey<Value>..., suite: UserDefaults = .standard) {
-		reset(keys, suite: suite)
-	}
 
 	/**
 	Reset the given optional keys back to `nil`.
@@ -228,31 +192,6 @@ public final class Defaults {
 	public static func reset<Value: NSSecureCoding>(_ keys: NSSecureCodingOptionalKey<Value>..., suite: UserDefaults = .standard) {
 		reset(keys, suite: suite)
 	}
-
-	/**
-	Reset the given array of optional keys back to `nil`.
-
-	- Parameter keys: Keys to reset.
-	- Parameter suite: `UserDefaults` suite.
-
-	```
-	extension Defaults.Keys {
-		static let unicorn = OptionalKey<String>("unicorn")
-	}
-
-	Defaults[.unicorn] = "🦄"
-
-	Defaults.reset(.unicorn)
-
-	Defaults[.unicorn]
-	//=> nil
-	```
-	*/
-	public static func reset<Value: Codable>(_ keys: [OptionalKey<Value>], suite: UserDefaults = .standard) {
-		for key in keys {
-			key.suite[key] = nil
-		}
-	}
 
 	/**
 	Reset the given array of optional keys back to `nil`.
@@ -277,6 +216,19 @@ public final class Defaults {
 	}
 }
 
+extension Defaults.Key where Value: _DefaultsOptionalType {
+	public convenience init(_ key: String, suite: UserDefaults = .standard) {
+		self.init(key, default: nil, suite: suite)
+	}
+}
+
+@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
+extension Defaults.NSSecureCodingKey where Value: _DefaultsOptionalType {
+	public convenience init(_ key: String, suite: UserDefaults = .standard) {
+		self.init(key, default: nil, suite: suite)
+	}
+}
+
 extension UserDefaults {
 	private func _get<Value: Codable>(_ key: String) -> Value? {
 		if UserDefaults.isNativelySupportedType(Value.self) {
@@ -334,6 +286,11 @@ extension UserDefaults {
 	}
 
 	private func _set<Value: Codable>(_ key: String, to value: Value) {
+		if (value as? _DefaultsOptionalType)?.isNil == true {
+			removeObject(forKey: key)
+			return
+		}
+
 		if UserDefaults.isNativelySupportedType(Value.self) {
 			set(value, forKey: key)
 			return
@@ -344,6 +301,7 @@ extension UserDefaults {
 
 	@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
 	private func _set<Value: NSSecureCoding>(_ key: String, to value: Value) {
+		// TODO: Handle nil here too.
 		if UserDefaults.isNativelySupportedType(Value.self) {
 			set(value, forKey: key)
 			return
@@ -367,18 +325,6 @@ extension UserDefaults {
 		}
 	}
 
-	public subscript<Value: Codable>(key: Defaults.OptionalKey<Value>) -> Value? {
-		get { _get(key.name) }
-		set {
-			guard let value = newValue else {
-				set(nil, forKey: key.name)
-				return
-			}
-
-			_set(key.name, to: value)
-		}
-	}
-
 	@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
 	public subscript<Value: NSSecureCoding>(key: Defaults.NSSecureCodingOptionalKey<Value>) -> Value? {
 		get { _get(key.name) }
@@ -392,16 +338,23 @@ extension UserDefaults {
 		}
 	}
 
-	fileprivate static func isNativelySupportedType<Value>(_ type: Value.Type) -> Bool {
+	fileprivate static func isNativelySupportedType<T>(_ type: T.Type) -> Bool {
 		switch type {
 		case
 			is Bool.Type,
+			is Bool?.Type, // swiftlint:disable:this discouraged_optional_boolean
 			is String.Type,
+			is String?.Type,
 			is Int.Type,
+			is Int?.Type,
 			is Double.Type,
+			is Double?.Type,
 			is Float.Type,
+			is Float?.Type,
 			is Date.Type,
-			is Data.Type:
+			is Date?.Type,
+			is Data.Type,
+			is Data?.Type:
 			return true
 		default:
 			return false

Sources/Defaults/Observation+Combine.swift

@@ -60,7 +60,7 @@ extension Defaults {
 			self.options = options
 		}
 
-		func receive<S>(subscriber: S) where S : Subscriber, DefaultsPublisher.Failure == S.Failure, DefaultsPublisher.Output == S.Input {
+		func receive<S>(subscriber: S) where S: Subscriber, Failure == S.Failure, Output == S.Input {
 			let subscription = DefaultsSubscription(
 				subscriber: subscriber,
 				suite: suite,
@@ -81,7 +81,7 @@ extension Defaults {
 		static let isUnicornMode = Key<Bool>("isUnicornMode", default: false)
 	}
 
-	let publisher = Defaults.publisher(.isUnicornMode).map { $0.newValue }
+	let publisher = Defaults.publisher(.isUnicornMode).map(\.newValue)
 
 	let cancellable = publisher.sink { value in
 		print(value)
@@ -114,20 +114,6 @@ extension Defaults {
 		return AnyPublisher(publisher)
 	}
 
-	/**
-	Returns a type-erased `Publisher` that publishes changes related to the given optional key.
-	*/
-	@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
-	public static func publisher<Value: Codable>(
-		_ key: Defaults.OptionalKey<Value>,
-		options: NSKeyValueObservingOptions = [.initial, .old, .new]
-	) -> AnyPublisher<OptionalKeyChange<Value>, Never> {
-		let publisher = DefaultsPublisher(suite: key.suite, key: key.name, options: options)
-			.map { OptionalKeyChange<Value>(change: $0) }
-
-		return AnyPublisher(publisher)
-	}
-
 	/**
 	Returns a type-erased `Publisher` that publishes changes related to the given optional key.
 	*/
@@ -154,29 +140,7 @@ extension Defaults {
 
 		let combinedPublisher =
 			keys.map { key in
-				return Defaults.publisher(key, options: options)
-					.map { _ in () }
-					.eraseToAnyPublisher()
-			}.reduce(initial) { (combined, keyPublisher) in
-				combined.merge(with: keyPublisher).eraseToAnyPublisher()
-			}
-
-		return combinedPublisher
-	}
-
-	/**
-	Publisher for multiple `OptionalKey<T>` observation, but without specific information about changes.
-	*/
-	@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
-	public static func publisher<Value: Codable>(
-		keys: Defaults.OptionalKey<Value>...,
-		options: NSKeyValueObservingOptions = [.initial, .old, .new]
-	) -> AnyPublisher<Void, Never> {
-		let initial = Empty<Void, Never>(completeImmediately: false).eraseToAnyPublisher()
-
-		let combinedPublisher =
-			keys.map { key in
-				return Defaults.publisher(key, options: options)
+				Defaults.publisher(key, options: options)
 					.map { _ in () }
 					.eraseToAnyPublisher()
 			}.reduce(initial) { (combined, keyPublisher) in
@@ -198,7 +162,7 @@ extension Defaults {
 
 		let combinedPublisher =
 			keys.map { key in
-				return Defaults.publisher(key, options: options)
+				Defaults.publisher(key, options: options)
 					.map { _ in () }
 					.eraseToAnyPublisher()
 			}.reduce(initial) { (combined, keyPublisher) in
@@ -220,7 +184,7 @@ extension Defaults {
 
 		let combinedPublisher =
 			keys.map { key in
-				return Defaults.publisher(key, options: options)
+				Defaults.publisher(key, options: options)
 					.map { _ in () }
 					.eraseToAnyPublisher()
 			}.reduce(initial) { (combined, keyPublisher) in

Sources/Defaults/Observation.swift

@@ -113,22 +113,6 @@ extension Defaults {
 		}
 	}
 
-	public struct OptionalKeyChange<Value: Codable> {
-		public let kind: NSKeyValueChange
-		public let indexes: IndexSet?
-		public let isPrior: Bool
-		public let newValue: Value?
-		public let oldValue: Value?
-
-		init(change: BaseChange) {
-			self.kind = change.kind
-			self.indexes = change.indexes
-			self.isPrior = change.isPrior
-			self.oldValue = deserialize(change.oldValue, to: Value.self)
-			self.newValue = deserialize(change.newValue, to: Value.self)
-		}
-	}
-
 	@available(iOS 11.0, macOS 10.13, tvOS 11.0, watchOS 4.0, iOSApplicationExtension 11.0, macOSApplicationExtension 10.13, tvOSApplicationExtension 11.0, watchOSApplicationExtension 4.0, *)
 	public struct NSSecureCodingOptionalKeyChange<Value: NSSecureCoding> {
 		public let kind: NSKeyValueChange
@@ -179,6 +163,7 @@ extension Defaults {
 			lifetimeAssociation = LifetimeAssociation(of: self, with: weaklyHeldObject, deinitHandler: { [weak self] in
 				self?.invalidate()
 			})
+
 			return self
 		}
 
@@ -255,34 +240,6 @@ extension Defaults {
 		return observation
 	}
 
-	/**
-	Observe an optional defaults key.
-
-	```
-	extension Defaults.Keys {
-		static let isUnicornMode = OptionalKey<Bool>("isUnicornMode")
-	}
-
-	let observer = Defaults.observe(.isUnicornMode) { change in
-		print(change.newValue)
-		//=> Optional(nil)
-	}
-	```
-	*/
-	public static func observe<Value: Codable>(
-		_ key: Defaults.OptionalKey<Value>,
-		options: NSKeyValueObservingOptions = [.initial, .old, .new],
-		handler: @escaping (OptionalKeyChange<Value>) -> Void
-	) -> DefaultsObservation {
-		let observation = UserDefaultsKeyObservation(object: key.suite, key: key.name) { change in
-			handler(
-				OptionalKeyChange<Value>(change: change)
-			)
-		}
-		observation.start(options: options)
-		return observation
-	}
-
 	/**
 	Observe an optional defaults key.
 	*/