a:7:{i:0;s:24:"X-Powered-By: PHP/5.3.28";i:1;s:38:"Expires: Wed, 11 Jan 1984 05:00:00 GMT";i:2;s:51:"Cache-Control: no-cache, must-revalidate, max-age=0";i:3;s:16:"Pragma: no-cache";i:4;s:54:"X-Pingback: http://www.mutation-testing.net/xmlrpc.php";i:5;s:38:"Content-Type: text/html; charset=UTF-8";i:6;s:60:"Link: ; rel=shortlink";} Arithmetic operator mutation - NinjaTurtles

The ArithmeticOperatorTurtle looks for the following IL OpCodes in your method:

* OpCodes.Add (addition, +)
* OpCodes.Sub (subtraction, -)
* OpCodes.Mul (multiplication, *)
* OpCodes.Div (division, /)
* OpCodes.Rem (modulo, %)

It replaces each with each of the others, forming a separate mutant each time. Thus a single addition operation will generate four mutants. The turtle applies this mutation at the IL level, simply replacing the OpCode for the instruction then re-saving the assembly before running a suitable subset of your tests.