From 3090248a3efc43d1d65d1950bf1799e46d62a925 Mon Sep 17 00:00:00 2001
From: Bandini Bhopi <bandinib@amazon.com>
Date: Sat, 12 Aug 2023 01:43:49 +0000
Subject: [PATCH] Refactor BaseConnectionPool empty method

Signed-off-by: Bandini Bhopi <bandinib@amazon.com>
---
 CHANGELOG.md                           |  1 +
 lib/pool/BaseConnectionPool.js         | 11 ++++++-----
 test/unit/base-connection-pool.test.js |  8 ++++++++
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ec9eabeae..b224ded94 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Bumps `eslint-config-prettier` from 8.8.0 to 9.0.0
 ### Changed
 - Make handling of long numerals an option that is disabled by default ([#557](https://github.com/opensearch-project/opensearch-js/pull/557))
+- Refactor BaseConnectionPool empty method so that callback will always get called even when there is no connection ([#585](https://github.com/opensearch-project/opensearch-js/pull/585)) 
 ### Deprecated
 ### Removed
 ### Fixed
diff --git a/lib/pool/BaseConnectionPool.js b/lib/pool/BaseConnectionPool.js
index 30c5ad8df..a01ec5f24 100644
--- a/lib/pool/BaseConnectionPool.js
+++ b/lib/pool/BaseConnectionPool.js
@@ -150,13 +150,14 @@ class BaseConnectionPool {
     let openConnections = this.size;
     this.connections.forEach((connection) => {
       connection.close(() => {
-        if (--openConnections === 0) {
-          this.connections = [];
-          this.size = this.connections.length;
-          callback();
-        }
+        openConnections--;
       });
     });
+    if (openConnections === 0) {
+      this.connections = [];
+      this.size = this.connections.length;
+      callback();
+    }
   }
 
   /**
diff --git a/test/unit/base-connection-pool.test.js b/test/unit/base-connection-pool.test.js
index 5b2ea5fc7..bb1842fb0 100644
--- a/test/unit/base-connection-pool.test.js
+++ b/test/unit/base-connection-pool.test.js
@@ -156,6 +156,14 @@ test('API', (t) => {
     t.end();
   });
 
+  t.test('empty with no connection', (t) => {
+    const pool = new BaseConnectionPool({ Connection });
+    t.equal(pool.connections.length, 0);
+    pool.empty();
+    t.equal(pool.size, 0);
+    t.end();
+  });
+
   t.test('urlToHost', (t) => {
     const pool = new BaseConnectionPool({ Connection });
     const url = 'http://localhost:9200';