Create a PartialObjectOperation type

We need a type that represents (when considering [1] at cb11ba8) RTO13's
"partial ObjectOperation"; namely an ObjectOperation without an objectId
property. This is something that is easy to represent in TypeScript but
a bit of a faff in Swift; we have to create a new type for it.

Code largely generated by Cursor at my instruction.

[1] ably/specification#353

Author: lawrence-forooghian

Sources/AblyLiveObjects/Protocol/ObjectMessage.swift

@@ -31,6 +31,19 @@ internal struct OutboundObjectMessage {
     internal var serialTimestamp: Date? // OM2j
 }
 
+/// A partial version of `ObjectOperation` that excludes the `objectId` property. Used for encoding initial values where the `objectId` is not yet known.
+///
+/// `ObjectOperation` delegates its encoding and decoding to `PartialObjectOperation`.
+internal struct PartialObjectOperation {
+    internal var action: WireEnum<ObjectOperationAction> // OOP3a
+    internal var mapOp: ObjectsMapOp? // OOP3c
+    internal var counterOp: WireObjectsCounterOp? // OOP3d
+    internal var map: ObjectsMap? // OOP3e
+    internal var counter: WireObjectsCounter? // OOP3f
+    internal var nonce: String? // OOP3g
+    internal var initialValue: String? // OOP3h
+}
+
 internal struct ObjectOperation {
     internal var action: WireEnum<ObjectOperationAction> // OOP3a
     internal var objectId: String // OOP3b
@@ -141,31 +154,95 @@ internal extension ObjectOperation {
         wireObjectOperation: WireObjectOperation,
         format: AblyPlugin.EncodingFormat
     ) throws(InternalError) {
-        action = wireObjectOperation.action
+        // Decode the objectId first since it's not part of PartialObjectOperation
         objectId = wireObjectOperation.objectId
-        mapOp = try wireObjectOperation.mapOp.map { wireObjectsMapOp throws(InternalError) in
+
+        // Delegate to PartialObjectOperation for decoding
+        let partialOperation = try PartialObjectOperation(
+            partialWireObjectOperation: PartialWireObjectOperation(
+                action: wireObjectOperation.action,
+                mapOp: wireObjectOperation.mapOp,
+                counterOp: wireObjectOperation.counterOp,
+                map: wireObjectOperation.map,
+                counter: wireObjectOperation.counter,
+                nonce: wireObjectOperation.nonce,
+                initialValue: wireObjectOperation.initialValue,
+            ),
+            format: format,
+        )
+
+        // Copy the decoded values
+        action = partialOperation.action
+        mapOp = partialOperation.mapOp
+        counterOp = partialOperation.counterOp
+        map = partialOperation.map
+        counter = partialOperation.counter
+        nonce = partialOperation.nonce
+        initialValue = partialOperation.initialValue
+    }
+
+    /// Converts this `ObjectOperation` to a `WireObjectOperation`, applying the data encoding rules of OD4.
+    ///
+    /// - Parameters:
+    ///   - format: The format to use when applying the encoding rules of OD4.
+    func toWire(format: AblyPlugin.EncodingFormat) -> WireObjectOperation {
+        let partialWireOperation = PartialObjectOperation(
+            action: action,
+            mapOp: mapOp,
+            counterOp: counterOp,
+            map: map,
+            counter: counter,
+            nonce: nonce,
+            initialValue: initialValue,
+        ).toWire(format: format)
+
+        // Create WireObjectOperation from PartialWireObjectOperation and add objectId
+        return WireObjectOperation(
+            action: partialWireOperation.action,
+            objectId: objectId,
+            mapOp: partialWireOperation.mapOp,
+            counterOp: partialWireOperation.counterOp,
+            map: partialWireOperation.map,
+            counter: partialWireOperation.counter,
+            nonce: partialWireOperation.nonce,
+            initialValue: partialWireOperation.initialValue,
+        )
+    }
+}
+
+internal extension PartialObjectOperation {
+    /// Initializes a `PartialObjectOperation` from a `PartialWireObjectOperation`, applying the data decoding rules of OD5.
+    ///
+    /// - Parameters:
+    ///   - format: The format to use when applying the decoding rules of OD5.
+    /// - Throws: `InternalError` if JSON or Base64 decoding fails.
+    init(
+        partialWireObjectOperation: PartialWireObjectOperation,
+        format: AblyPlugin.EncodingFormat
+    ) throws(InternalError) {
+        action = partialWireObjectOperation.action
+        mapOp = try partialWireObjectOperation.mapOp.map { wireObjectsMapOp throws(InternalError) in
             try .init(wireObjectsMapOp: wireObjectsMapOp, format: format)
         }
-        counterOp = wireObjectOperation.counterOp
-        map = try wireObjectOperation.map.map { wireMap throws(InternalError) in
+        counterOp = partialWireObjectOperation.counterOp
+        map = try partialWireObjectOperation.map.map { wireMap throws(InternalError) in
             try .init(wireObjectsMap: wireMap, format: format)
         }
-        counter = wireObjectOperation.counter
+        counter = partialWireObjectOperation.counter
 
         // Do not access on inbound data, per OOP3g
         nonce = nil
         // Do not access on inbound data, per OOP3h
         initialValue = nil
     }
 
-    /// Converts this `ObjectOperation` to a `WireObjectOperation`, applying the data encoding rules of OD4.
+    /// Converts this `PartialObjectOperation` to a `PartialWireObjectOperation`, applying the data encoding rules of OD4.
     ///
     /// - Parameters:
     ///   - format: The format to use when applying the encoding rules of OD4.
-    func toWire(format: AblyPlugin.EncodingFormat) -> WireObjectOperation {
+    func toWire(format: AblyPlugin.EncodingFormat) -> PartialWireObjectOperation {
         .init(
             action: action,
-            objectId: objectId,
             mapOp: mapOp?.toWire(format: format),
             counterOp: counterOp,
             map: map?.toWire(format: format),

Sources/AblyLiveObjects/Protocol/WireObjectMessage.swift

@@ -157,9 +157,11 @@ internal enum ObjectsMapSemantics: Int {
     case lww = 0
 }
 
-internal struct WireObjectOperation {
+/// A partial version of `WireObjectOperation` that excludes the `objectId` property. Used for encoding initial values where the `objectId` is not yet known.
+///
+/// `WireObjectOperation` delegates its encoding and decoding to `PartialWireObjectOperation`.
+internal struct PartialWireObjectOperation {
     internal var action: WireEnum<ObjectOperationAction> // OOP3a
-    internal var objectId: String // OOP3b
     internal var mapOp: WireObjectsMapOp? // OOP3c
     internal var counterOp: WireObjectsCounterOp? // OOP3d
     internal var map: WireObjectsMap? // OOP3e
@@ -168,10 +170,9 @@ internal struct WireObjectOperation {
     internal var initialValue: String? // OOP3h
 }
 
-extension WireObjectOperation: WireObjectCodable {
+extension PartialWireObjectOperation: WireObjectCodable {
     internal enum WireKey: String {
         case action
-        case objectId
         case mapOp
         case counterOp
         case map
@@ -182,7 +183,6 @@ extension WireObjectOperation: WireObjectCodable {
 
     internal init(wireObject: [String: WireValue]) throws(InternalError) {
         action = try wireObject.wireEnumValueForKey(WireKey.action.rawValue)
-        objectId = try wireObject.stringValueForKey(WireKey.objectId.rawValue)
         mapOp = try wireObject.optionalDecodableValueForKey(WireKey.mapOp.rawValue)
         counterOp = try wireObject.optionalDecodableValueForKey(WireKey.counterOp.rawValue)
         map = try wireObject.optionalDecodableValueForKey(WireKey.map.rawValue)
@@ -197,7 +197,6 @@ extension WireObjectOperation: WireObjectCodable {
     internal var toWireObject: [String: WireValue] {
         var result: [String: WireValue] = [
             WireKey.action.rawValue: .number(action.rawValue as NSNumber),
-            WireKey.objectId.rawValue: .string(objectId),
         ]
 
         if let mapOp {
@@ -223,6 +222,57 @@ extension WireObjectOperation: WireObjectCodable {
     }
 }
 
+internal struct WireObjectOperation {
+    internal var action: WireEnum<ObjectOperationAction> // OOP3a
+    internal var objectId: String // OOP3b
+    internal var mapOp: WireObjectsMapOp? // OOP3c
+    internal var counterOp: WireObjectsCounterOp? // OOP3d
+    internal var map: WireObjectsMap? // OOP3e
+    internal var counter: WireObjectsCounter? // OOP3f
+    internal var nonce: String? // OOP3g
+    internal var initialValue: String? // OOP3h
+}
+
+extension WireObjectOperation: WireObjectCodable {
+    internal enum WireKey: String {
+        case objectId
+    }
+
+    internal init(wireObject: [String: WireValue]) throws(InternalError) {
+        // Decode the objectId first since it's not part of PartialWireObjectOperation
+        objectId = try wireObject.stringValueForKey(WireKey.objectId.rawValue)
+
+        // Delegate to PartialWireObjectOperation for decoding
+        let partialOperation = try PartialWireObjectOperation(wireObject: wireObject)
+
+        // Copy the decoded values
+        action = partialOperation.action
+        mapOp = partialOperation.mapOp
+        counterOp = partialOperation.counterOp
+        map = partialOperation.map
+        counter = partialOperation.counter
+        nonce = partialOperation.nonce
+        initialValue = partialOperation.initialValue
+    }
+
+    internal var toWireObject: [String: WireValue] {
+        var result = PartialWireObjectOperation(
+            action: action,
+            mapOp: mapOp,
+            counterOp: counterOp,
+            map: map,
+            counter: counter,
+            nonce: nonce,
+            initialValue: initialValue,
+        ).toWireObject
+
+        // Add the objectId field
+        result[WireKey.objectId.rawValue] = .string(objectId)
+
+        return result
+    }
+}
+
 internal struct WireObjectState {
     internal var objectId: String // OST2a
     internal var siteTimeserials: [String: String] // OST2b