Fix Two Operands exception

Author: cbalda

.travis.yml

@@ -10,5 +10,5 @@ before_script:
 script:
  - phpunit
 
-after_script: 
+after_script:
  - php vendor/bin/coveralls -v

src/SQLParser/Node/NodeFactory.php

@@ -33,6 +33,7 @@
 namespace SQLParser\Node;
 
 use Mouf\Database\MagicQueryException;
+use Mouf\Database\MagicQueryParserException;
 use SQLParser\SqlRenderInterface;
 use Doctrine\DBAL\Connection;
 use Mouf\MoufManager;
@@ -620,16 +621,16 @@ public static function simplify($nodes)
         */
 
         if (isset(self::$OPERATOR_TO_CLASS[$operation]) && is_subclass_of(self::$OPERATOR_TO_CLASS[$operation], 'SQLParser\Node\AbstractTwoOperandsOperator')) {
-            $leftOperand = array_shift($operands);
-            while (!empty($operands)) {
-                $rightOperand = array_shift($operands);
-
-                $instance = new self::$OPERATOR_TO_CLASS[$operation]();
-                $instance->setLeftOperand($leftOperand);
-                $instance->setRightOperand($rightOperand);
-                $leftOperand = $instance;
+            if (count($operands) !== 2) {
+                throw new MagicQueryParserException("Expected exactly 2 operands on ".self::$OPERATOR_TO_CLASS[$operation].". Found ".count($operands));
             }
 
+            $leftOperand = array_shift($operands);
+            $rightOperand = array_shift($operands);
+            $instance = new self::$OPERATOR_TO_CLASS[$operation]();
+            $instance->setLeftOperand($leftOperand);
+            $instance->setRightOperand($rightOperand);
+
             return $instance;
         } elseif (isset(self::$OPERATOR_TO_CLASS[$operation]) && is_subclass_of(self::$OPERATOR_TO_CLASS[$operation], 'SQLParser\Node\AbstractManyInstancesOperator')) {
             $instance = new self::$OPERATOR_TO_CLASS[$operation]();