Refactor Occupancy events

[ECO-5342]

Author: ttypic

Example/AblyChatExample/ContentView.swift

@@ -350,9 +350,9 @@ struct ContentView: View {
     }
 
     func subscribeToOccupancy(room: Room) {
-        room.occupancy.subscribe { occupancy in
+        room.occupancy.subscribe { event in
             withAnimation {
-                occupancyInfo = "Connections: \(occupancy.presenceMembers) (\(occupancy.connections))"
+                occupancyInfo = "Connections: \(event.occupancy.presenceMembers) (\(event.occupancy.connections))"
             }
         }
     }

Example/AblyChatExample/Mocks/MockClients.swift

@@ -536,15 +536,16 @@ class MockOccupancy: Occupancy {
         mockSubscriptions.create(
             randomElement: {
                 let random = Int.random(in: 1 ... 10)
-                return OccupancyEvent(connections: random, presenceMembers: Int.random(in: 0 ... random))
+                let occupancyData = OccupancyData(connections: random, presenceMembers: Int.random(in: 0 ... random))
+                return OccupancyEvent(type: .updated, occupancy: occupancyData)
             },
             interval: 2,
             callback: callback
         )
     }
 
-    func get() async throws(ARTErrorInfo) -> OccupancyEvent {
-        OccupancyEvent(connections: 10, presenceMembers: 5)
+    func get() async throws(ARTErrorInfo) -> OccupancyData {
+        OccupancyData(connections: 10, presenceMembers: 5)
     }
 }
 

Sources/AblyChat/ChatAPI.swift

@@ -192,7 +192,7 @@ internal final class ChatAPI: Sendable {
         return message
     }
 
-    internal func getOccupancy(roomName: String) async throws(InternalError) -> OccupancyEvent {
+    internal func getOccupancy(roomName: String) async throws(InternalError) -> OccupancyData {
         let endpoint = "\(apiVersionV3)/rooms/\(roomName)/occupancy"
         return try await makeRequest(endpoint, method: "GET")
     }

Sources/AblyChat/DefaultOccupancy.swift

@@ -12,7 +12,7 @@ internal final class DefaultOccupancy: Occupancy {
         implementation.subscribe(callback)
     }
 
-    internal func get() async throws(ARTErrorInfo) -> OccupancyEvent {
+    internal func get() async throws(ARTErrorInfo) -> OccupancyData {
         try await implementation.get()
     }
 
@@ -58,7 +58,8 @@ internal final class DefaultOccupancy: Occupancy {
                 let connections = metrics["connections"] as? Int ?? 0
                 let presenceMembers = metrics["presenceMembers"] as? Int ?? 0
 
-                let occupancyEvent = OccupancyEvent(connections: connections, presenceMembers: presenceMembers)
+                let occupancyData = OccupancyData(connections: connections, presenceMembers: presenceMembers)
+                let occupancyEvent = OccupancyEvent(type: .updated, occupancy: occupancyData)
                 logger.log(message: "Emitting occupancy event: \(occupancyEvent)", level: .debug)
                 callback(occupancyEvent)
             }
@@ -72,7 +73,7 @@ internal final class DefaultOccupancy: Occupancy {
         }
 
         // (CHA-O3) Users can request an instantaneous occupancy check via the REST API. The request is detailed here (https://sdk.ably.com/builds/ably/specification/main/chat-features/#rest-occupancy-request), with the response format being a simple occupancy event
-        internal func get() async throws(ARTErrorInfo) -> OccupancyEvent {
+        internal func get() async throws(ARTErrorInfo) -> OccupancyData {
             do {
                 logger.log(message: "Getting occupancy for room: \(roomName)", level: .debug)
                 return try await chatAPI.getOccupancy(roomName: roomName)

Sources/AblyChat/Occupancy.swift

@@ -26,7 +26,7 @@ public protocol Occupancy: AnyObject, Sendable {
      *
      * - Returns: A current occupancy of the chat room.
      */
-    func get() async throws(ARTErrorInfo) -> OccupancyEvent
+    func get() async throws(ARTErrorInfo) -> OccupancyData
 }
 
 /// `AsyncSequence` variant of receiving room occupancy events.
@@ -44,8 +44,8 @@ public extension Occupancy {
     func subscribe(bufferingPolicy: BufferingPolicy) -> SubscriptionAsyncSequence<OccupancyEvent> {
         let subscriptionAsyncSequence = SubscriptionAsyncSequence<OccupancyEvent>(bufferingPolicy: bufferingPolicy)
 
-        let subscription = subscribe { occupancy in
-            subscriptionAsyncSequence.emit(occupancy)
+        let subscription = subscribe { occupancyEvent in
+            subscriptionAsyncSequence.emit(occupancyEvent)
         }
 
         subscriptionAsyncSequence.addTerminationHandler {
@@ -68,7 +68,7 @@ public extension Occupancy {
 /**
  * Represents the occupancy of a chat room.
  */
-public struct OccupancyEvent: Sendable {
+public struct OccupancyData: Sendable {
     /**
      * The number of connections to the chat room.
      */
@@ -85,7 +85,21 @@ public struct OccupancyEvent: Sendable {
     }
 }
 
-extension OccupancyEvent: JSONObjectDecodable {
+public enum OccupancyEventType: String, Sendable {
+    case updated
+}
+
+public struct OccupancyEvent: Sendable {
+    public let type: OccupancyEventType
+    public let occupancy: OccupancyData
+
+    public init(type: OccupancyEventType, occupancy: OccupancyData) {
+        self.type = type
+        self.occupancy = occupancy
+    }
+}
+
+extension OccupancyData: JSONObjectDecodable {
     internal init(jsonObject: [String: JSONValue]) throws(InternalError) {
         try self.init(
             connections: Int(jsonObject.numberValueForKey("connections")),

Tests/AblyChatTests/DefaultRoomOccupancyTests.swift

@@ -58,11 +58,12 @@ struct DefaultRoomOccupancyTests {
 
         // When
         let subscription = defaultOccupancy.subscribe()
-        subscription.emit(OccupancyEvent(connections: 5, presenceMembers: 2))
+        let occupancyData = OccupancyData(connections: 5, presenceMembers: 2)
+        subscription.emit(OccupancyEvent(type: .updated, occupancy: occupancyData))
 
         // Then
-        let occupancyInfo = try #require(await subscription.first { @Sendable _ in true })
-        #expect(occupancyInfo.connections == 5)
-        #expect(occupancyInfo.presenceMembers == 2)
+        let occupancyEvent = try #require(await subscription.first { @Sendable _ in true })
+        #expect(occupancyEvent.occupancy.connections == 5)
+        #expect(occupancyEvent.occupancy.presenceMembers == 2)
     }
 }

Tests/AblyChatTests/IntegrationTests.swift

@@ -9,7 +9,7 @@ extension Tag {
 
 /// Some very basic integration tests, just to check that things are kind of working.
 ///
-/// It would be nice to give this a time limit, but unfortunately the `timeLimit` trait is only available on iOS 16 etc and above. CodeRabbit suggested writing a timeout function myself and wrapping the contents of the test in it, but I didn’t have time to try understanding its suggested code, so it can wait.
+/// It would be nice to give this a time limit, but unfortunately the `timeLimit` trait is only available on iOS 16 etc and above. CodeRabbit suggested writing a timeout function myself and wrapping the contents of the test in it, but I didn't have time to try understanding its suggested code, so it can wait.
 @Suite(.tags(.integration))
 @MainActor
 struct IntegrationTests {
@@ -106,7 +106,7 @@ struct IntegrationTests {
 
         // (1) Send a message before subscribing to messages, so that later on we can check history works.
 
-        // (2) Create a throwaway subscription and wait for it to receive a message. This is to make sure that rxRoom has seen the message that we send here, so that the first message we receive on the subscription created in (5) is that which we’ll send in (6), and not that which we send here.
+        // (2) Create a throwaway subscription and wait for it to receive a message. This is to make sure that rxRoom has seen the message that we send here, so that the first message we receive on the subscription created in (5) is that which we'll send in (6), and not that which we send here.
         let throwawayRxMessageSubscription = try await rxRoom.messages.subscribe()
 
         // (3) Send the message
@@ -123,7 +123,7 @@ struct IntegrationTests {
         // (5) Subscribe to messages
         let rxMessageSubscription = try await rxRoom.messages.subscribe()
 
-        // (6) Now that we’re subscribed to messages, send a message on the other client and check that we receive it on the subscription
+        // (6) Now that we're subscribed to messages, send a message on the other client and check that we receive it on the subscription
         let txMessageAfterRxSubscribe = try await txRoom.messages.send(
             params: .init(
                 text: "Hello from txRoom, after rxRoom subscribe",
@@ -227,15 +227,15 @@ struct IntegrationTests {
          https://ably-real-time.slack.com/archives/C03JDBVM5MY/p1733220395208909
          that
 
-         > new materialised history system doesn’t currently support “live”
-         > history (realtime implementation detail) - so we’re approximating the
+         > new materialised history system doesn't currently support "live"
+         > history (realtime implementation detail) - so we're approximating the
          > behaviour
 
          and indicated that the right workaround for now is to introduce a
          wait. So we retry the fetching of history until we get a non-empty
          result.
 
-         Revert this (https://github.com/ably/ably-chat-swift/issues/175) once it’s fixed in Realtime.
+         Revert this (https://github.com/ably/ably-chat-swift/issues/175) once it's fixed in Realtime.
          */
         let rxMessagesHistory = try await {
             while true {
@@ -323,7 +323,7 @@ struct IntegrationTests {
         // (1) Subscribe to reactions
         let rxReactionSubscription = rxRoom.reactions.subscribe()
 
-        // (2) Now that we’re subscribed to reactions, send a reaction on the other client and check that we receive it on the subscription
+        // (2) Now that we're subscribed to reactions, send a reaction on the other client and check that we receive it on the subscription
         try await txRoom.reactions.send(
             params: .init(
                 type: "heart",
@@ -338,7 +338,7 @@ struct IntegrationTests {
 
         // MARK: - Occupancy
 
-        // It can take a moment for the occupancy to update from the clients connecting above, so we’ll wait a 2 seconds here.
+        // It can take a moment for the occupancy to update from the clients connecting above, so we'll wait a 2 seconds here.
         try await Task.sleep(nanoseconds: 2_000_000_000)
 
         // (1) Get current occupancy
@@ -357,7 +357,7 @@ struct IntegrationTests {
 
         // (5) Check that we received an updated presence count on the subscription
         _ = try #require(await rxOccupancySubscription.first { @Sendable occupancyEvent in
-            occupancyEvent.presenceMembers == 1 // 1 for txClient entering presence
+            occupancyEvent.occupancy.presenceMembers == 1 // 1 for txClient entering presence
         })
 
         // (6) Check that we received an updated presence count when getting the occupancy
@@ -369,7 +369,7 @@ struct IntegrationTests {
 
         // (8) Check that we received an updated presence count on the subscription
         _ = try #require(await rxOccupancySubscription.first { @Sendable occupancyEvent in
-            occupancyEvent.presenceMembers == 0 // 0 for txClient leaving presence
+            occupancyEvent.occupancy.presenceMembers == 0 // 0 for txClient leaving presence
         })
 
         // (9) Check that we received an updated presence count when getting the occupancy
@@ -509,7 +509,7 @@ struct IntegrationTests {
         })
         #expect(rxRoom.status == .released)
 
-        // (3) Fetch the room we just released and check it’s a new object
+        // (3) Fetch the room we just released and check it's a new object
         let postReleaseRxRoom = try await rxClient.rooms.get(name: roomName, options: .init())
         #expect(postReleaseRxRoom !== rxRoom)
     }