/** * @test */ public function I_can_create_new_number_by_adding_value() { $number = new NumberObject(123); $increased = $number->add(456); self::assertSame(123, $number->getValue()); self::assertSame(579, $increased->getValue()); self::assertNotEquals($number, $increased); $increasedMore = $increased->add($number); self::assertSame(702, $increasedMore->getValue()); }