Address comments

Author: minggangw

lib/publisher.js

@@ -75,7 +75,7 @@ class Publisher extends Entity {
 
   /**
    * Get the number of subscriptions to this publisher.
-   * @returns {number} The number of subscription
+   * @returns {number} The number of subscriptions
    */
   get subscriptionCount() {
     return rclnodejs.getSubscriptionCount(this._handle);

test/test-publisher.js

@@ -44,7 +44,7 @@ describe('rclnodejs publisher test suite', function () {
     rclnodejs.spin(node);
   });
 
-  it('Test count of subscription', function () {
+  it('Test count of subscriptions', function () {
     const node = rclnodejs.createNode('publisher_node');
     const String = 'std_msgs/msg/String';
     const publisher = node.createPublisher(String, 'topic');