fix: proper coding styl

Author: Dimitri Nikitopoulos

src/lib/RosNode.js

@@ -122,8 +122,10 @@ class RosNode extends EventEmitter {
     if (callback && typeof callback === 'function') {
       sub.on('message', callback);
     }
-    if (!firstSubscriber && subImpl._latching && subImpl._lastMessage){
-        sub.emit('message', subImpl._lastMessage)
+    // Duplicate subscribers wont get a latched 'message' emit from the existing subscriber impl.
+    // This will forcibly send an emit if the topic is latched and has already seen an incoming message
+    if (!firstSubscriber && subImpl.getLatching() && subImpl.getLastMessage()) {
+        sub.emit('message', subImpl.getLastMessage())
     }
 
     return sub;

src/lib/impl/SubscriberImpl.js

@@ -134,6 +134,23 @@ class SubscriberImpl extends EventEmitter {
     return this._nodeHandle;
   }
 
+  /**
+   * Check if this subscriber is connected to a latched topic
+   * @returns {boolean}
+   */
+  getLatching() {
+    return this._latching;
+  }
+
+  /**
+   * Return the last message received
+   * @returns {any}
+   */
+  getLastMessage() {
+    return this._lastMessage;
+  }
+
+
   /**
    * Clears and closes all client connections for this subscriber.
    */
@@ -425,7 +442,7 @@ class SubscriberImpl extends EventEmitter {
   _handleMsgQueue(msgQueue) {
     try {
       msgQueue.forEach((msg) => {
-        if(this._latching){
+        if (this.getLatching()) {
           this._lastMessage = this._messageHandler.deserialize(msg);
         }
         this.emit('message', this._messageHandler.deserialize(msg));