test_array_in_chunks.rb

require 'test/unit'
require 'enumerator'

class Array
  def in_chunks_of(size_of_chunks)
    enum_slice(size_of_chunks).to_a
  end
end

class TestArrayInChunks < Test::Unit::TestCase
  def test_chunking_equal_to_size
    assert_equal [1, 2].in_chunks_of(2), [[1, 2]]
  end
  
  def test_chunk_greater_than_size
    assert_equal [1, 2].in_chunks_of(4), [[1, 2]]
  end
  
  def test_even_chunks
    assert_equal [1, 2, 3, 4].in_chunks_of(2), [[1, 2], [3, 4]]
  end
  
  def test_more_than_two_chunks
    assert_equal [1, 2, 3, 4, 5, 6].in_chunks_of(2), [[1, 2], [3, 4], [5, 6]]
  end
  
  def test_more_than_two_chunks_with_remainder
    assert_equal [1, 2, 3, 4, 5, 6, 7].in_chunks_of(2), [[1, 2], [3, 4], [5, 6], [7]]
  end
end