public void IfTooLong() { var veryLong = "very long"; Assert.Throws <DesignByContractViolationException>( () => Fail.IfToLong(veryLong, 3, nameof(veryLong)) ); Fail.IfToLong(null, 300, "null"); Fail.IfToLong("aa", 300, "aa"); Fail.IfToLong("aa", 2, "aa"); }