fix(pool): getConnection callback should be called only once

Author: fenying

lib/pool.js

@@ -81,20 +81,23 @@ class Pool extends EventEmitter {
 
     if (this.config.acquireTimeout > 0) {
 
-      const timeout = setTimeout(() => {
+      // eslint-disable-next-line prefer-const
+      let timer;
 
-        spliceConnection(this._connectionQueue, cb);
-        cb(new Error('Timeout acquiring connection'));
-
-      }, this.config.acquireTimeout);
+      const wrappedCb = (err, connection) => {
 
-      return this._connectionQueue.push((err, connection) => {
+        clearTimeout(timer);
+        cb(err, connection);
+      };
 
-        clearTimeout(timeout);
+      timer = setTimeout(() => {
 
-        cb(err, connection);
+        spliceConnection(this._connectionQueue, wrappedCb);
+        cb(new Error('Timeout acquiring connection'));
 
       }, this.config.acquireTimeout);
+
+      return this._connectionQueue.push(wrappedCb);
     }
 
     return this._connectionQueue.push(cb);

test/integration/test-pool-acquire-timeout.js

@@ -1,9 +1,8 @@
 'use strict';
 
 const mysql = require('../..');
-const test = require('utest');
 const assert = require('assert');
-const common = require('../common');
+const common = require('../common.test.cjs');
 
 const poolConfig = common.getConfig();
 
@@ -15,33 +14,34 @@ const poolWithAcquireTimeout = new mysql.createPool({
 });
 
 poolWithAcquireTimeout.getConnection((err, c1) => {
+  
   assert.equal(!!c1, true);
   assert.ifError(err);
+
   poolWithAcquireTimeout.getConnection((err, c2) => {
+
     assert.ifError(err);
     assert.equal(!!c2, true);
+
     const C3_STARTED_AT = Date.now();
+
     poolWithAcquireTimeout.getConnection((e3, c3) => {
       const C3_DONE_AT = Date.now();
+      assert.equal(C3_DONE_AT - C3_STARTED_AT >= ACQUIRE_TIMEOUT, true);
+      assert.equal(C3_DONE_AT - C3_STARTED_AT < ACQUIRE_TIMEOUT * 2, true);
 
-      poolWithAcquireTimeout.releaseConnection(c1);
+      assert.notEqual(e3, null);
+      assert.equal(!c3, true);
+      c1.release();
 
       poolWithAcquireTimeout.getConnection((e4, c4) => {
 
-        test('Pool With Acquire Timeout', {
-          'timeout of pool is full': () => {
-            assert.equal(e3 !== null, true);
-            assert.equal(!c3, true);
-            assert.equal(C3_DONE_AT - C3_STARTED_AT >= ACQUIRE_TIMEOUT, true);
-            assert.equal(C3_DONE_AT - C3_STARTED_AT < ACQUIRE_TIMEOUT * 2, true);
-          },
-          'ok if pool is not full': () => {
-            assert.equal(e4 === null, true);
-            assert.equal(!!c4, true);
-          }
-        });
-    
-        poolWithAcquireTimeout.releaseConnection(c4);
+        assert.equal(e4, null);
+        assert.equal(!!c4, true);
+
+        c4.release();
+        c2.release();
+        poolWithAcquireTimeout.end();
       });
     });
   });