Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: master
Fetching contributors…

Cannot retrieve contributors at this time

file 87 lines (65 sloc) 2.051 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87
require File.expand_path(File.dirname(__FILE__) + '/edgecase')

C = "top level"

class AboutConstants < EdgeCase::Koan

  C = "nested"

  def test_nested_constants_may_also_be_referenced_with_relative_paths
    assert_equal "nested", C
  end

  def test_top_level_constants_are_referenced_by_double_colons
    assert_equal "top level", ::C
  end

  def test_nested_constants_are_referenced_by_their_complete_path
    assert_equal "nested", AboutConstants::C
    assert_equal "nested", ::AboutConstants::C
  end

  # ------------------------------------------------------------------

  class Animal
    LEGS = 4
    def legs_in_animal
      LEGS
    end

    class NestedAnimal
      def legs_in_nested_animal
        LEGS
      end
    end
  end

  def test_nested_classes_inherit_constants_from_enclosing_classes
    assert_equal 4, Animal::NestedAnimal.new.legs_in_nested_animal
  end

  # ------------------------------------------------------------------

  class Reptile < Animal
    def legs_in_reptile
      LEGS
    end
  end

  def test_subclasses_inherit_constants_from_parent_classes
    assert_equal 4, Reptile.new.legs_in_reptile
  end

  # ------------------------------------------------------------------

  class MyAnimals
    LEGS = 2

    class Bird < Animal
      def legs_in_bird
        LEGS
      end
    end
  end

  def test_who_wins_with_both_nested_and_inherited_constants
    assert_equal 2, MyAnimals::Bird.new.legs_in_bird
  end

  # QUESTION: Which has precedence: The constant in the lexical scope,
  # or the constant from the inheritance heirarachy?

  # ------------------------------------------------------------------

  class MyAnimals::Oyster < Animal
    def legs_in_oyster
      LEGS
    end
  end

  def test_who_wins_with_explicit_scoping_on_class_definition
    assert_equal 4, MyAnimals::Oyster.new.legs_in_oyster
  end

  # QUESTION: Now Which has precedence: The constant in the lexical
  # scope, or the constant from the inheritance heirarachy? Why is it
  # different than the previous answer?
end
Something went wrong with that request. Please try again.