Add POOL_CLOSED code to "Pool is closed." error

Author: dougwilson

Changes.md

@@ -6,6 +6,7 @@ you spot any mistakes.
 
 ## HEAD
 
+* Add `POOL_CLOSED` code to "Pool is closed." error
 * Add `POOL_CONNLIMIT` code to "No connections available." error #1332
 * Fix Query stream to emit close after ending #1349 #1350
 * Fix type cast for BIGINT columns when number is negative #1376

lib/Pool.js

@@ -22,8 +22,10 @@ function Pool(options) {
 Pool.prototype.getConnection = function (cb) {
 
   if (this._closed) {
+    var err = new Error('Pool is closed.');
+    err.code = 'POOL_CLOSED';
     process.nextTick(function () {
-      cb(new Error('Pool is closed.'));
+      cb(err);
     });
     return;
   }
@@ -48,6 +50,7 @@ Pool.prototype.getConnection = function (cb) {
 
       if (pool._closed) {
         err = new Error('Pool is closed.');
+        err.code = 'POOL_CLOSED';
       }
 
       if (err) {
@@ -89,6 +92,7 @@ Pool.prototype.acquireConnection = function acquireConnection(connection, cb) {
 
     if (pool._closed) {
       err = new Error('Pool is closed.');
+      err.code = 'POOL_CLOSED';
     }
 
     if (err) {
@@ -115,7 +119,6 @@ Pool.prototype.acquireConnection = function acquireConnection(connection, cb) {
 };
 
 Pool.prototype.releaseConnection = function releaseConnection(connection) {
-  var cb;
   var pool = this;
 
   if (this._acquiringConnections.indexOf(connection) !== -1) {
@@ -138,17 +141,18 @@ Pool.prototype.releaseConnection = function releaseConnection(connection) {
     }
   }
 
-  while (this._closed && this._connectionQueue.length) {
+  if (this._closed) {
     // empty the connection queue
-    cb = this._connectionQueue.shift();
-
-    process.nextTick(cb.bind(null, new Error('Pool is closed.')));
-  }
-
-  if (this._connectionQueue.length) {
-    cb = this._connectionQueue.shift();
-
-    this.getConnection(cb);
+    this._connectionQueue.splice(0).forEach(function (cb) {
+      var err = new Error('Pool is closed.');
+      err.code = 'POOL_CLOSED';
+      process.nextTick(function () {
+        cb(err);
+      });
+    });
+  } else if (this._connectionQueue.length) {
+    // get connection with next waiting callback
+    this.getConnection(this._connectionQueue.shift());
   }
 };
 

test/unit/pool/test-end-ping.js

@@ -22,6 +22,7 @@ server.listen(common.fakeServerPort, function (err) {
     pool.getConnection(function (err, conn) {
       assert.ok(err);
       assert.equal(err.message, 'Pool is closed.');
+      assert.equal(err.code, 'POOL_CLOSED');
     });
 
     pool.end(function (err) {

test/unit/pool/test-end-queued.js

@@ -41,5 +41,7 @@ process.on('exit', function() {
   assert.ok(conn1Err);
   assert.ok(conn2Err);
   assert.equal(conn1Err.message, 'Pool is closed.');
-  assert.equal(conn2Err.message, 'Pool is closed.');
+  assert.equal(conn2Err.code, 'POOL_CLOSED');
+  assert.equal(conn1Err.message, 'Pool is closed.');
+  assert.equal(conn2Err.code, 'POOL_CLOSED');
 });