Readme.md

#Pancake.flatten

###about:

Returns a new array that is a one-dimensional flattening of nested arrays (recursively).

###usage:

Pancake.flatten(array)

###examples:

a = [1, 2, [3, 4], 'five']
b = [1, 2, [[3, 4], ['five', [6, 7]], 8]]
Pancake.flatten(a)  #returns [1, 2, 3, 4, 'five']
Pancake.flatten(b)  #returns [1, 2, 3, 4, "five", 6, 7, 8]`

###specs: Run bundle install to install minitest dependencies. Then run ruby pancake_spec.rb

Gemfile

source "https://rubygems.org"

gem "minitest"

pancake.rb

class Pancake

  def self.flatten(list)
    flattened = []
    list.map do |item|
      flattened += (item.is_a?(Array) ? Pancake.flatten(item) : [item])
    end
    flattened
  end

end

pancake_spec.rb

require_relative 'pancake'
require 'minitest/autorun'

class TestPancake < Minitest::Test

  def setup
    @nested_array = [1, 2, [3, 4], 'five']
    @deeply_nested_array = [1, 2, [[3, 4], ['five', [6, 7]], 8]]
  end

  def test_flattens_nested_array
    assert_equal [1, 2, 3, 4, 'five'], Pancake.flatten(@nested_array)
  end

  def test_flattens_deeply_nested_array
    assert_equal [1, 2, 3, 4, "five", 6, 7, 8], Pancake.flatten(@deeply_nested_array)
  end

end