fix: separation of concerns

src/common/BatchedTransport.js

@@ -10,11 +10,13 @@ class BatchedTransport {
     this._transport.addListener(BATCHED_TRANSPORT_CHANNEL, stack => {
       stack.forEach(entry => {
         const [channel, args] = entry;
-        const callbacks = this._listeners.get(channel);
-
-        callbacks.forEach(callback => {
-          callback(...args);
-        });
+        // server side the transport is the same EventEmitter instance
+        // for both state manager server and client, so channel might not exist
+        // one side or the other.
+        if (this._listeners.has(channel)) {
+          const callbacks = this._listeners.get(channel);
+          callbacks.forEach(callback => callback(...args));
+        };
       });
     });
   }

src/server/StateManager.js

@@ -323,7 +323,7 @@ class StateManager extends BaseStateManager {
     this._observers = new Set();
     this._hooksBySchemaName = new Map(); // protected
 
-    this.addClient(localClientId, this.client.transport);
+    this.addClient(localClientId, localTransport);
   }
 
   [kIsObservableState](state) {
@@ -345,11 +345,7 @@ class StateManager extends BaseStateManager {
    * @private
    */
   addClient(nodeId, transport) {
-    // server adds itself as client, and its transport is a raw EventEmitter
-    // so we don't want to proxy it twice with BatchedTransport.
-    if (nodeId !== SERVER_ID) {
-      transport = new BatchedTransport(transport);
-    }
+    transport = new BatchedTransport(transport);
 
     const client = { id: nodeId, transport };
     this._clientByNodeId.set(nodeId, client);