Fix early detection of bad callback to connection.query

Author: dougwilson

Changes.md

@@ -6,6 +6,7 @@ you spot any mistakes.
 
 ## HEAD
 
+* Fix early detection of bad callback to `connection.query`
 * Support Node.js 12.x #2211
 * Support Node.js 13.x
 * Update `bignumber.js` to 9.0.0

lib/Connection.js

@@ -500,7 +500,11 @@ function unwrapFromDomain(fn) {
 }
 
 function wrapCallbackInDomain(ee, fn) {
-  if (typeof fn !== 'function' || fn.domain) {
+  if (typeof fn !== 'function') {
+    return undefined;
+  }
+
+  if (fn.domain) {
     return fn;
   }
 

test/unit/query/test-args-query-bad-callback.js

@@ -0,0 +1,16 @@
+var assert     = require('assert');
+var common     = require('../../common');
+var connection = common.createConnection({port: common.fakeServerPort});
+
+var server = common.createFakeServer();
+
+server.listen(common.fakeServerPort, function (err) {
+  assert.ifError(err);
+
+  assert.throws(function () {
+    connection.query('SELECT ?', [1], 'oops');
+  }, /TypeError: argument callback must be a function when provided/);
+
+  connection.destroy();
+  server.destroy();
+});