feat(client-presence): Create Acknowledgment message interface and ackRequested flow

packages/framework/presence/src/presenceDatastoreManager.ts

@@ -90,9 +90,21 @@ interface ClientJoinMessage extends IInboundSignalMessage {
 	};
 }
 
+// Message type identifier for presence acknowledgment messages.
+const acknowledgementMessageType = "Pres:Ack";
+
+// Signal message format used to acknowledge receipt of presence-related messages.
+// These are lightweight and typically contain only the messageId being acknowledged.
+interface AcknowledgementMessage extends IInboundSignalMessage {
+	type: typeof acknowledgementMessageType;
+	// TODO: Define what ack content will be shaped like ({ messageId: string }),
+	// Keeping generic for now to allow evolution of this message type.
+	content: unknown;
+}
+
 function isPresenceMessage(
 	message: IInboundSignalMessage,
-): message is DatastoreUpdateMessage | ClientJoinMessage {
+): message is DatastoreUpdateMessage | ClientJoinMessage | AcknowledgementMessage {
 	return message.type.startsWith("Pres:");
 }
 /**
@@ -356,14 +368,26 @@ export class PresenceDatastoreManagerImpl implements PresenceDatastoreManager {
 		// IExtensionMessage is a subset of IInboundSignalMessage so this is safe.
 		// Change types of DatastoreUpdateMessage | ClientJoinMessage to
 		// IExtensionMessage<> derivatives to see the issues.
-		message: IInboundSignalMessage | DatastoreUpdateMessage | ClientJoinMessage,
+		message:
+			| IInboundSignalMessage
+			| DatastoreUpdateMessage
+			| ClientJoinMessage
+			| AcknowledgementMessage,
 		local: boolean,
 	): void {
 		const received = Date.now();
 		assert(message.clientId !== null, 0xa3a /* Map received signal without clientId */);
 		if (!isPresenceMessage(message)) {
 			return;
 		}
+
+		// Here we accept acknowledgement messages passively.
+		// Once implemented, these will be used for tracking message delivery status.
+		// For now, we just skip processing these messages.
+		if (message.type === acknowledgementMessageType) {
+			return;
+		}
+
 		if (local) {
 			const deliveryDelta = received - message.content.sendTimestamp;
 			// Limit returnedMessages count to 256 such that newest message

packages/framework/presence/src/test/presenceDatastoreManager.spec.ts

@@ -438,5 +438,32 @@ describe("Presence", () => {
 				assert.strictEqual(listener.callCount, 1);
 			});
 		});
+
+		describe("receiving AcknowledgementMessage", () => {
+			it("accepts passively without failing", () => {
+				const presence = prepareConnectedPresence(
+					runtime,
+					"attendeeId-2",
+					"client2",
+					clock,
+					logger,
+				);
+				// This test ensures that PresenceManager can safely receive and process
+				// a signal of type 'Pres:Ack' without throwing or misbehaving,
+				// even if the acknowledgment does not correspond to any known pending message.
+				// We do not assert specific outcomes here — success is defined by the absence of error
+				presence.processSignal(
+					"",
+					{
+						type: "Pres:Ack",
+						content: {
+							messageId: "messageId", // Arbitrary ID that is not expected to match anything
+						},
+						clientId: "client1",
+					},
+					false,
+				);
+			});
+		});
 	});
 });