fix: implement pool_connection end

Author: dimov

Diff for: lib/pool.js

@@ -127,7 +127,7 @@ class Pool extends EventEmitter {
     }
     for (let i = 0; i < this._allConnections.length; i++) {
       connection = this._allConnections.get(i);
-      connection._realEnd(endCB);
+      connection.end(endCB);
     }
   }
 
@@ -205,7 +205,7 @@ class Pool extends EventEmitter {
             Date.now() - this._freeConnections.get(0).lastActiveTime >
               this.config.idleTimeout)
         ) {
-          this._freeConnections.get(0)._realEnd();
+          this._freeConnections.get(0).end();
         }
       } finally {
         this._removeIdleTimeoutConnections();

Diff for: lib/pool_connection.js

@@ -34,17 +34,9 @@ class PoolConnection extends Connection {
     return new PromisePoolConnection(this, promiseImpl);
   }
 
-  end() {
-    const err = new Error(
-      'Calling conn.end() to release a pooled connection is ' +
-        'deprecated. In next version calling conn.end() will be ' +
-        'restored to default conn.end() behavior. Use ' +
-        'conn.release() instead.'
-    );
-    this.emit('warn', err);
-    // eslint-disable-next-line no-console
-    console.warn(err.message);
-    this.release();
+  end(callback) {
+    this._removeFromPool();
+    super.end(callback);
   }
 
   destroy() {
@@ -64,6 +56,3 @@ class PoolConnection extends Connection {
 
 PoolConnection.statementKey = Connection.statementKey;
 module.exports = PoolConnection;
-
-// TODO: Remove this when we are removing PoolConnection#end
-PoolConnection.prototype._realEnd = Connection.prototype.end;