citrusbyte

test_array_functions.rb

require "test/unit"

module ArrayFunctions
  class << self
    def flatten(array, flatten_array = [])
      raise "Nothing to do" unless array

      array.each do |element|
        if element.is_a? Integer
          flatten_array << element
        elsif element.is_a? Array
          flatten element, flatten_array
        else
          raise "Not a valid object"
        end
      end

      flatten_array
    end
  end
end

class TestArrayFunctions < Test::Unit::TestCase
  def test_simple_nesting
    assert_equal [1,2], ArrayFunctions.flatten([1,[2]])
  end

  def test_simple_nesting_with_empty_elements
    assert_equal [1,2], ArrayFunctions.flatten([1,[2],[],[[]]])
  end

  def test_a_bit_complex_nesting_with_empty_elements
    assert_equal [1,2,3], ArrayFunctions.flatten([1,[2],[],[[3]]])
  end

  def test_an_apparent_filled_array
    assert_equal [], ArrayFunctions.flatten([[],[],[],[[]]])
  end

  def test_deep_nesting
    assert_equal [1,2,3,4,5,6,7], ArrayFunctions.flatten([1,[2,[3,4],5],6,[7]])
  end

  def test_nil_object
    assert_raise("Nothing to do") { ArrayFunctions.flatten(nil) }
  end

  def test_not_a_valid_object
    assert_raise("Not a valid object") { ArrayFunctions.flatten([2, {}]) }
  end
end