Enable the ExistentialAny upcoming language feature

Done with `swift package migrate --to-feature ExistentialAny`.

Author: lawrence-forooghian

Package.swift

@@ -4,6 +4,7 @@ import PackageDescription
 
 let commonSwiftSettings: [SwiftSetting] = [
     .enableUpcomingFeature("MemberImportVisibility"),
+    .enableUpcomingFeature("ExistentialAny"),
 ]
 
 let package = Package(

Sources/AblyChat/ChatClient.swift

@@ -66,7 +66,7 @@ public class DefaultChatClient: ChatClient {
         _rooms
     }
 
-    private let logger: InternalLogger
+    private let logger: any InternalLogger
 
     // (CHA-CS1) Every chat client has a status, which describes the current status of the connection.
     // (CHA-CS4) The chat client must allow its connection status to be observed by clients.
@@ -121,7 +121,7 @@ public struct ChatClientOptions: Sendable {
      *
      * By default, the client will log messages to the console.
      */
-    public var logHandler: LogHandler?
+    public var logHandler: (any LogHandler)?
 
     /**
      * The minimum log level at which messages will be logged.

Sources/AblyChat/Connection.swift

@@ -25,7 +25,7 @@ public protocol Connection: AnyObject, Sendable {
      * - Returns: A subscription that can be used to unsubscribe from ``ConnectionStatusChange`` events.
      */
     @discardableResult
-    func onStatusChange(_ callback: @escaping @MainActor (ConnectionStatusChange) -> Void) -> StatusSubscriptionProtocol
+    func onStatusChange(_ callback: @escaping @MainActor (ConnectionStatusChange) -> Void) -> any StatusSubscriptionProtocol
 }
 
 /// `AsyncSequence` variant of `Connection` status changes.

Sources/AblyChat/DefaultConnection.swift

@@ -21,7 +21,7 @@ internal final class DefaultConnection: Connection {
 
     // (CHA-CS4d) Clients must be able to register a listener for connection status events and receive such events.
     @discardableResult
-    internal func onStatusChange(_ callback: @escaping @MainActor (ConnectionStatusChange) -> Void) -> StatusSubscriptionProtocol {
+    internal func onStatusChange(_ callback: @escaping @MainActor (ConnectionStatusChange) -> Void) -> any StatusSubscriptionProtocol {
         // (CHA-CS5) The chat client must monitor the underlying realtime connection for connection status changes.
         let eventListener = realtime.connection.on { [weak self] stateChange in
             guard let self else {

Sources/AblyChat/DefaultMessageReactions.swift

@@ -4,12 +4,12 @@ import Ably
 internal final class DefaultMessageReactions: MessageReactions {
     private let channel: any InternalRealtimeChannelProtocol
     private let roomName: String
-    private let logger: InternalLogger
+    private let logger: any InternalLogger
     private let clientID: String
     private let chatAPI: ChatAPI
     private let options: MessagesOptions
 
-    internal init(channel: any InternalRealtimeChannelProtocol, chatAPI: ChatAPI, roomName: String, options: MessagesOptions, clientID: String, logger: InternalLogger) {
+    internal init(channel: any InternalRealtimeChannelProtocol, chatAPI: ChatAPI, roomName: String, options: MessagesOptions, clientID: String, logger: any InternalLogger) {
         self.channel = channel
         self.chatAPI = chatAPI
         self.roomName = roomName
@@ -60,7 +60,7 @@ internal final class DefaultMessageReactions: MessageReactions {
 
     // (CHA-MR6) Users must be able to subscribe to message reaction summaries via the subscribe method of the MessagesReactions object. The events emitted will be of type MessageReactionSummaryEvent.
     @discardableResult
-    internal func subscribe(_ callback: @escaping @MainActor @Sendable (MessageReactionSummaryEvent) -> Void) -> SubscriptionProtocol {
+    internal func subscribe(_ callback: @escaping @MainActor @Sendable (MessageReactionSummaryEvent) -> Void) -> any SubscriptionProtocol {
         logger.log(message: "Subscribing to message reaction summary events", level: .debug)
 
         let eventListener = channel.subscribe { [weak self] message in
@@ -101,7 +101,7 @@ internal final class DefaultMessageReactions: MessageReactions {
 
     // (CHA-MR7) Users must be able to subscribe to raw message reactions (as individual annotations) via the subscribeRaw method of the MessagesReactions object. The events emitted are of type MessageReactionRawEvent.
     @discardableResult
-    internal func subscribeRaw(_ callback: @escaping @MainActor @Sendable (MessageReactionRawEvent) -> Void) -> SubscriptionProtocol {
+    internal func subscribeRaw(_ callback: @escaping @MainActor @Sendable (MessageReactionRawEvent) -> Void) -> any SubscriptionProtocol {
         logger.log(message: "Subscribing to reaction events", level: .debug)
         guard options.rawMessageReactions else {
             // (CHA-MR7a) The attempt to subscribe to raw message reactions must throw an ErrorInfo with code 40000 and status code 400 if the room is not configured to support raw message reactions

Sources/AblyChat/DefaultMessages.swift

@@ -8,7 +8,7 @@ internal final class DefaultMessages: Messages {
     private let roomName: String
     private let chatAPI: ChatAPI
     private let clientID: String
-    private let logger: InternalLogger
+    private let logger: any InternalLogger
 
     private var currentSubscriptionPoint: String?
     private var subscriptionPoints: [UUID: String] = [:]
@@ -26,7 +26,7 @@ internal final class DefaultMessages: Messages {
         }
     }
 
-    internal init(channel: any InternalRealtimeChannelProtocol, chatAPI: ChatAPI, roomName: String, options: MessagesOptions = .init(), clientID: String, logger: InternalLogger) {
+    internal init(channel: any InternalRealtimeChannelProtocol, chatAPI: ChatAPI, roomName: String, options: MessagesOptions = .init(), clientID: String, logger: any InternalLogger) {
         self.channel = channel
         self.chatAPI = chatAPI
         self.roomName = roomName
@@ -36,7 +36,7 @@ internal final class DefaultMessages: Messages {
         updateCurrentSubscriptionPoint()
     }
 
-    internal func subscribe(_ callback: @escaping @MainActor (ChatMessageEvent) -> Void) -> MessageSubscriptionResponseProtocol {
+    internal func subscribe(_ callback: @escaping @MainActor (ChatMessageEvent) -> Void) -> any MessageSubscriptionResponseProtocol {
         logger.log(message: "Subscribing to messages", level: .debug)
         // (CHA-M4c) When a realtime message with name set to message.created is received, it is translated into a message event, which contains a type field with the event type as well as a message field containing the Message Struct. This event is then broadcast to all subscribers.
         // (CHA-M4d) If a realtime message with an unknown name is received, the SDK shall silently discard the message, though it may log at DEBUG or TRACE level.

Sources/AblyChat/DefaultOccupancy.swift

@@ -4,12 +4,12 @@ internal final class DefaultOccupancy: Occupancy {
     private let channel: any InternalRealtimeChannelProtocol
     private let chatAPI: ChatAPI
     private let roomName: String
-    private let logger: InternalLogger
+    private let logger: any InternalLogger
     private let options: OccupancyOptions
 
     private var lastOccupancyData: OccupancyData?
 
-    internal init(channel: any InternalRealtimeChannelProtocol, chatAPI: ChatAPI, roomName: String, logger: InternalLogger, options: OccupancyOptions) {
+    internal init(channel: any InternalRealtimeChannelProtocol, chatAPI: ChatAPI, roomName: String, logger: any InternalLogger, options: OccupancyOptions) {
         self.channel = channel
         self.chatAPI = chatAPI
         self.roomName = roomName
@@ -18,7 +18,7 @@ internal final class DefaultOccupancy: Occupancy {
     }
 
     @discardableResult
-    internal func subscribe(_ callback: @escaping @MainActor (OccupancyEvent) -> Void) -> SubscriptionProtocol {
+    internal func subscribe(_ callback: @escaping @MainActor (OccupancyEvent) -> Void) -> any SubscriptionProtocol {
         // CHA-O4e (we use a fatalError for this programmer error, which is the idiomatic thing to do for Swift)
         guard options.enableEvents else {
             fatalError("In order to be able to subscribe to presence events, please set enableEvents to true in the room's occupancy options.")

Sources/AblyChat/DefaultPresence.swift

@@ -5,10 +5,10 @@ internal final class DefaultPresence: Presence {
     private let roomLifecycleManager: any RoomLifecycleManager
     private let roomName: String
     private let clientID: String
-    private let logger: InternalLogger
+    private let logger: any InternalLogger
     private let options: PresenceOptions
 
-    internal init(channel: any InternalRealtimeChannelProtocol, roomLifecycleManager: any RoomLifecycleManager, roomName: String, clientID: String, logger: InternalLogger, options: PresenceOptions) {
+    internal init(channel: any InternalRealtimeChannelProtocol, roomLifecycleManager: any RoomLifecycleManager, roomName: String, clientID: String, logger: any InternalLogger, options: PresenceOptions) {
         self.channel = channel
         self.roomLifecycleManager = roomLifecycleManager
         self.roomName = roomName
@@ -199,7 +199,7 @@ internal final class DefaultPresence: Presence {
 
     // (CHA-PR7a) Users may provide a listener to subscribe to all presence events in a room.
     // (CHA-PR7b) Users may provide a listener and a list of selected presence events, to subscribe to just those events in a room.
-    internal func subscribe(event: PresenceEventType, _ callback: @escaping @MainActor (PresenceEvent) -> Void) -> SubscriptionProtocol {
+    internal func subscribe(event: PresenceEventType, _ callback: @escaping @MainActor (PresenceEvent) -> Void) -> any SubscriptionProtocol {
         fatalErrorIfEnableEventsDisabled()
 
         logger.log(message: "Subscribing to presence events", level: .debug)
@@ -221,7 +221,7 @@ internal final class DefaultPresence: Presence {
         }
     }
 
-    internal func subscribe(events: [PresenceEventType], _ callback: @escaping @MainActor (PresenceEvent) -> Void) -> SubscriptionProtocol {
+    internal func subscribe(events: [PresenceEventType], _ callback: @escaping @MainActor (PresenceEvent) -> Void) -> any SubscriptionProtocol {
         fatalErrorIfEnableEventsDisabled()
 
         logger.log(message: "Subscribing to presence events", level: .debug)

Sources/AblyChat/DefaultRoomReactions.swift

@@ -3,10 +3,10 @@ import Ably
 internal final class DefaultRoomReactions: RoomReactions {
     private let channel: any InternalRealtimeChannelProtocol
     private let roomName: String
-    private let logger: InternalLogger
+    private let logger: any InternalLogger
     private let clientID: String
 
-    internal init(channel: any InternalRealtimeChannelProtocol, clientID: String, roomName: String, logger: InternalLogger) {
+    internal init(channel: any InternalRealtimeChannelProtocol, clientID: String, roomName: String, logger: any InternalLogger) {
         self.roomName = roomName
         self.channel = channel
         self.logger = logger
@@ -34,7 +34,7 @@ internal final class DefaultRoomReactions: RoomReactions {
     // (CHA-ER4) A user may subscribe to reaction events in Realtime.
     // (CHA-ER4a) A user may provide a listener to subscribe to reaction events. This operation must have no side-effects in relation to room or underlying status. When a realtime message with name roomReaction is received, this message is converted into a reaction object and emitted to subscribers.
     @discardableResult
-    internal func subscribe(_ callback: @escaping @MainActor (RoomReactionEvent) -> Void) -> SubscriptionProtocol {
+    internal func subscribe(_ callback: @escaping @MainActor (RoomReactionEvent) -> Void) -> any SubscriptionProtocol {
         logger.log(message: "Subscribing to reaction events", level: .debug)
 
         // (CHA-ER4c) Realtime events with an unknown name shall be silently discarded.

Sources/AblyChat/DefaultTyping.swift

@@ -4,21 +4,21 @@ internal final class DefaultTyping: Typing {
     private let channel: any InternalRealtimeChannelProtocol
     private let roomName: String
     private let clientID: String
-    private let logger: InternalLogger
+    private let logger: any InternalLogger
     private let heartbeatThrottle: TimeInterval
 
     // (CHA-T10a) A grace period shall be set by the client (the grace period on the CHA-T10 heartbeat interval when receiving events). The default value shall be set to 2000ms.
     private let gracePeriod: TimeInterval = 2
 
-    private let typingTimerManager: TypingTimerManagerProtocol
+    private let typingTimerManager: any TypingTimerManagerProtocol
 
     // (CHA-T14) Multiple asynchronous calls to keystroke/stop typing must eventually converge to a consistent state.
     // (CHA-TM14a) When a call to keystroke or stop is made, it should attempt to acquire a mutex lock.
     // (CHA-TM14b) Once the lock is acquired, if another call is made to either function, the second call shall be queued and wait until it can acquire the lock before executing.
     // (CHA-TM14b1) During this time, each new subsequent call to either function shall abort the previously queued call. In doing so, there shall only ever be one pending call and while the mutex is held, thus the most recent call shall "win" and execute once the mutex is released.
     private let keyboardOperationQueue = TypingOperationQueue<InternalError>()
 
-    internal init(channel: any InternalRealtimeChannelProtocol, roomName: String, clientID: String, logger: InternalLogger, heartbeatThrottle: TimeInterval, clock: some ClockProtocol) {
+    internal init(channel: any InternalRealtimeChannelProtocol, roomName: String, clientID: String, logger: any InternalLogger, heartbeatThrottle: TimeInterval, clock: some ClockProtocol) {
         self.roomName = roomName
         self.channel = channel
         self.clientID = clientID
@@ -35,7 +35,7 @@ internal final class DefaultTyping: Typing {
 
     // (CHA-T6) Users may subscribe to typing events – updates to a set of clientIDs that are typing. This operation, like all subscription operations, has no side-effects in relation to room lifecycle.
     @discardableResult
-    internal func subscribe(_ callback: @escaping @MainActor (TypingSetEvent) -> Void) -> SubscriptionProtocol {
+    internal func subscribe(_ callback: @escaping @MainActor (TypingSetEvent) -> Void) -> any SubscriptionProtocol {
         // (CHA-T6a) Users may provide a listener to subscribe to typing event V2 in a chat room.
         let startedEventListener = channel.subscribe(TypingEventType.started.rawValue) { [weak self] message in
             guard let self, let messageClientID = message.clientId else {