require File.expand_path(File.dirname(__FILE__) + '/edgecase') class AboutObjects < EdgeCase::Koan def test_everything_is_an_object assert_equal __, 1.is_a?(Object) assert_equal __, 1.5.is_a?(Object) assert_equal __, "string".is_a?(Object) assert_equal __, nil.is_a?(Object) assert_equal __, Object.is_a?(Object) end def test_objects_can_be_converted_to_strings assert_equal __, 123.to_s assert_equal __, nil.to_s end def test_objects_can_be_inspected assert_equal __, 123.inspect assert_equal __, nil.inspect end def test_every_object_has_an_id obj = Object.new assert_equal __, obj.object_id.class end def test_every_object_has_different_id obj = Object.new another_obj = Object.new assert_equal __, obj.object_id != another_obj.object_id end def test_some_system_objects_always_have_the_same_id assert_equal __, false.object_id assert_equal __, true.object_id assert_equal __, nil.object_id end def test_small_integers_have_fixed_ids assert_equal __, 0.object_id assert_equal __, 1.object_id assert_equal __, 2.object_id assert_equal __, 100.object_id # THINK ABOUT IT: # What pattern do the object IDs for small integers follow? end def test_clone_creates_a_different_object obj = Object.new copy = obj.clone assert_equal __, obj != copy assert_equal __, obj.object_id != copy.object_id end end