88 lines
2.0 KiB
Ruby
88 lines
2.0 KiB
Ruby
require File.expand_path(File.dirname(__FILE__) + '/neo')
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C = "top level"
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class AboutConstants < Neo::Koan
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C = "nested"
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def test_nested_constants_may_also_be_referenced_with_relative_paths
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assert_equal __, C
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end
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def test_top_level_constants_are_referenced_by_double_colons
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assert_equal __, ::C
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end
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def test_nested_constants_are_referenced_by_their_complete_path
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assert_equal __, AboutConstants::C
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assert_equal __, ::AboutConstants::C
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end
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# ------------------------------------------------------------------
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class Animal
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LEGS = 4
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def legs_in_animal
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LEGS
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end
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class NestedAnimal
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def legs_in_nested_animal
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LEGS
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end
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end
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end
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def test_nested_classes_inherit_constants_from_enclosing_classes
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assert_equal __, Animal::NestedAnimal.new.legs_in_nested_animal
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end
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# ------------------------------------------------------------------
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class Reptile < Animal
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def legs_in_reptile
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LEGS
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end
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end
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def test_subclasses_inherit_constants_from_parent_classes
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assert_equal __, Reptile.new.legs_in_reptile
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end
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# ------------------------------------------------------------------
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class MyAnimals
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LEGS = 2
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class Bird < Animal
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def legs_in_bird
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LEGS
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end
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end
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end
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def test_who_wins_with_both_nested_and_inherited_constants
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assert_equal __, MyAnimals::Bird.new.legs_in_bird
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end
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# QUESTION: Which has precedence: The constant in the lexical scope,
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# or the constant from the inheritance hierarchy?
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# ------------------------------------------------------------------
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class MyAnimals::Oyster < Animal
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def legs_in_oyster
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LEGS
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end
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end
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def test_who_wins_with_explicit_scoping_on_class_definition
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assert_equal __, MyAnimals::Oyster.new.legs_in_oyster
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end
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# QUESTION: Now which has precedence: The constant in the lexical
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# scope, or the constant from the inheritance hierarchy? Why is it
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# different than the previous answer?
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end
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