Clean up constantly initialized class members

package.json

@@ -19,6 +19,7 @@
   "devDependencies": {
     "@testing-library/react": "^14.2.1",
     "@types/node": "^20.11.19",
+    "@types/ws": "^8.5.10",
     "eslint": "^8.56.0",
     "globals": "^14.0.0",
     "jsdoc": "^4.0.2",

src/actionlib/ActionClient.js

@@ -19,6 +19,9 @@ import { EventEmitter } from 'eventemitter3';
  *
  */
 export default class ActionClient extends EventEmitter {
+  goals = {};
+  /** flag to check if a status has been received */
+  receivedStatus = false
   /**
    * @param {Object} options
    * @param {Ros} options.ros - The ROSLIB.Ros connection handle.
@@ -31,18 +34,13 @@ export default class ActionClient extends EventEmitter {
    */
   constructor(options) {
     super();
-    var that = this;
     this.ros = options.ros;
     this.serverName = options.serverName;
     this.actionName = options.actionName;
     this.timeout = options.timeout;
     this.omitFeedback = options.omitFeedback;
     this.omitStatus = options.omitStatus;
     this.omitResult = options.omitResult;
-    this.goals = {};
-
-    // flag to check if a status has been received
-    var receivedStatus = false;
 
     // create the topics associated with actionlib
     this.feedbackListener = new Topic({
@@ -81,10 +79,10 @@ export default class ActionClient extends EventEmitter {
 
     // subscribe to the status topic
     if (!this.omitStatus) {
-      this.statusListener.subscribe(function (statusMessage) {
-        receivedStatus = true;
-        statusMessage.status_list.forEach(function (status) {
-          var goal = that.goals[status.goal_id.id];
+      this.statusListener.subscribe((statusMessage) => {
+        this.receivedStatus = true;
+        statusMessage.status_list.forEach((status) => {
+          var goal = this.goals[status.goal_id.id];
           if (goal) {
             goal.emit('status', status);
           }
@@ -94,8 +92,8 @@ export default class ActionClient extends EventEmitter {
 
     // subscribe the the feedback topic
     if (!this.omitFeedback) {
-      this.feedbackListener.subscribe(function (feedbackMessage) {
-        var goal = that.goals[feedbackMessage.status.goal_id.id];
+      this.feedbackListener.subscribe((feedbackMessage) => {
+        var goal = this.goals[feedbackMessage.status.goal_id.id];
         if (goal) {
           goal.emit('status', feedbackMessage.status);
           goal.emit('feedback', feedbackMessage.feedback);
@@ -105,8 +103,8 @@ export default class ActionClient extends EventEmitter {
 
     // subscribe to the result topic
     if (!this.omitResult) {
-      this.resultListener.subscribe(function (resultMessage) {
-        var goal = that.goals[resultMessage.status.goal_id.id];
+      this.resultListener.subscribe((resultMessage) => {
+        var goal = this.goals[resultMessage.status.goal_id.id];
 
         if (goal) {
           goal.emit('status', resultMessage.status);
@@ -117,9 +115,9 @@ export default class ActionClient extends EventEmitter {
 
     // If timeout specified, emit a 'timeout' event if the action server does not respond
     if (this.timeout) {
-      setTimeout(function () {
-        if (!receivedStatus) {
-          that.emit('timeout');
+      setTimeout(() => {
+        if (!this.receivedStatus) {
+          this.emit('timeout');
         }
       }, this.timeout);
     }

src/actionlib/ActionListener.js

@@ -27,7 +27,6 @@ export default class ActionListener extends EventEmitter {
    */
   constructor(options) {
     super();
-    var that = this;
     this.ros = options.ros;
     this.serverName = options.serverName;
     this.actionName = options.actionName;
@@ -57,25 +56,25 @@ export default class ActionListener extends EventEmitter {
       messageType: this.actionName + 'Result'
     });
 
-    goalListener.subscribe(function (goalMessage) {
-      that.emit('goal', goalMessage);
+    goalListener.subscribe((goalMessage) => {
+      this.emit('goal', goalMessage);
     });
 
-    statusListener.subscribe(function (statusMessage) {
-      statusMessage.status_list.forEach(function (status) {
-        that.emit('status', status);
+    statusListener.subscribe((statusMessage) => {
+      statusMessage.status_list.forEach((status) => {
+        this.emit('status', status);
       });
     });
 
-    feedbackListener.subscribe(function (feedbackMessage) {
-      that.emit('status', feedbackMessage.status);
-      that.emit('feedback', feedbackMessage.feedback);
+    feedbackListener.subscribe((feedbackMessage) => {
+      this.emit('status', feedbackMessage.status);
+      this.emit('feedback', feedbackMessage.feedback);
     });
 
     // subscribe to the result topic
-    resultListener.subscribe(function (resultMessage) {
-      that.emit('status', resultMessage.status);
-      that.emit('result', resultMessage.result);
+    resultListener.subscribe((resultMessage) => {
+      this.emit('status', resultMessage.status);
+      this.emit('result', resultMessage.result);
     });
   }
 }

src/actionlib/Goal.js

@@ -14,26 +14,21 @@ import ActionClient from './ActionClient.js';
  *  * 'timeout' - If a timeout occurred while sending a goal.
  */
 export default class Goal extends EventEmitter {
+  isFinished = false;
+  status = undefined;
+  result = undefined;
+  feedback = undefined;
+  // Create a random ID
+  goalID = 'goal_' + Math.random() + '_' + new Date().getTime();
   /**
    * @param {Object} options
    * @param {ActionClient} options.actionClient - The ROSLIB.ActionClient to use with this goal.
    * @param {Object} options.goalMessage - The JSON object containing the goal for the action server.
    */
   constructor(options) {
     super();
-    var that = this;
     this.actionClient = options.actionClient;
-    this.goalMessage = options.goalMessage;
-    this.isFinished = false;
-    this.status = undefined;
-    this.result = undefined;
-    this.feedback = undefined;
 
-    // Used to create random IDs
-    var date = new Date();
-
-    // Create a random ID
-    this.goalID = 'goal_' + Math.random() + '_' + date.getTime();
     // Fill in the goal message
     this.goalMessage = {
       goal_id: {
@@ -43,20 +38,20 @@ export default class Goal extends EventEmitter {
         },
         id: this.goalID
       },
-      goal: this.goalMessage
+      goal: options.goalMessage
     };
 
-    this.on('status', function (status) {
-      that.status = status;
+    this.on('status', (status) => {
+      this.status = status;
     });
 
-    this.on('result', function (result) {
-      that.isFinished = true;
-      that.result = result;
+    this.on('result', (result) => {
+      this.isFinished = true;
+      this.result = result;
     });
 
-    this.on('feedback', function (feedback) {
-      that.feedback = feedback;
+    this.on('feedback', (feedback) => {
+      this.feedback = feedback;
     });
 
     // Add the goal
@@ -68,12 +63,11 @@ export default class Goal extends EventEmitter {
    * @param {number} [timeout] - A timeout length for the goal's result.
    */
   send(timeout) {
-    var that = this;
-    that.actionClient.goalTopic.publish(that.goalMessage);
+    this.actionClient.goalTopic.publish(this.goalMessage);
     if (timeout) {
-      setTimeout(function () {
-        if (!that.isFinished) {
-          that.emit('timeout');
+      setTimeout(() => {
+        if (!this.isFinished) {
+          this.emit('timeout');
         }
       }, timeout);
     }