Ensure removal of all idle connections in the free connection list of the connection pool (Issue #1633)

Author: sharadraju

doc/src/release_notes.rst

@@ -23,6 +23,11 @@ Thin Mode Changes
     unless the number of batch errors is a multiple of 65536; instead,
     the number of batch errors returned is modulo 65536.
 
+#)  Updated pool functionality to scan and remove idle connections from
+    beginning of free connection list. This will ensure removal of all idle
+    connections present in free connection list.
+    `Issue #1633 <https://github.com/oracle/node-oracledb/issues/1633>`__.
+
 Thick Mode Changes
 ++++++++++++++++++
 

lib/thin/pool.js

@@ -363,13 +363,13 @@ class ThinPoolImpl extends PoolImpl {
   _scanIdleConnection() {
     while ((this._usedConnectionList.size + this._freeConnectionList.length) >
         this._poolMin && this._freeConnectionList.length > 0) {
-      const conn = this._freeConnectionList[this._freeConnectionList.length - 1];
+      const conn = this._freeConnectionList[0];
       if (Date.now() - conn._lastTimeUsed < this._poolTimeout * 1000) {
         break;
       }
 
       this.eventEmitter.emit('_removePoolConnection', conn);
-      this._freeConnectionList.pop();
+      this._freeConnectionList.shift();
     }
 
     this._schedulerJob = null;