Issue #2080117 by Enxebre, mcrittenden: Add assertion to...

Issue #2080117 by Enxebre, mcrittenden: Add assertion to Drupal/system/Tests/Database/DeleteTruncateTest.php.

core/modules/system/lib/Drupal/system/Tests/Database/DeleteTruncateTest.php

@@ -69,6 +69,7 @@ function testSimpleDelete() {
    */
   function testTruncate() {
     $num_records_before = db_query("SELECT COUNT(*) FROM {test}")->fetchField();
+    $this->assertTrue($num_records_before > 0, 'The table is not empty.');
 
     db_truncate('test')->execute();