gistfile1.rb

require 'test/unit'

module ArrayExtension
  def superjoin(args={})
    start  = args[:start]
    before = args[:before]
    joiner = args[:join]
    after  = args[:after]
    ender  = args[:end]
    
    "#{start}#{self.map {|e| "#{before}#{e}#{after}"}.join(joiner)}#{ender}"
  end
end

class ArrayExtensionTest < Test::Unit::TestCase  
  def setup
    Array.send(:include, ArrayExtension)
    @array = %w[a b c]
  end
  
  def test_superjoin_should_accept_no_arguments
    assert_nothing_raised(ArgumentError) { @array.superjoin() }
  end

  def test_superjoin_without_arguments_should_return_a_flattened_string
    assert_equal('abc', @array.superjoin())
  end
  
  def test_superjoin_should_accept_before_argument
    assert_nothing_raised(ArgumentError) { @array.superjoin(:before => '*') }
  end

  def test_before_argument_should_prepend_string_to_each_element
    assert_equal('*a*b*c', @array.superjoin(:before => '*'))
  end

  def test_superjoin_should_accept_after_argument
    assert_nothing_raised(ArgumentError) { @array.superjoin(:after => '~') }
  end
  
  def test_after_argument_should_append_string_to_each_element
    assert_equal('a~b~c~', @array.superjoin(:after => '~'))
  end
  
  def test_superjoin_should_accept_join_argument
    assert_nothing_raised(ArgumentError) { @array.superjoin(:join => '-') }
  end
  
  def test_join_argument_should_append_string_between_each_element
    assert_equal('a-b-c', @array.superjoin(:join => '-'))
  end

  def test_superjoin_should_accept_start_argument
    assert_nothing_raised(ArgumentError) { @array.superjoin(:start => '<') }
  end
  
  def test_start_argument_should_prepend_string_before_all_others
    assert_equal('<abc', @array.superjoin(:start => '<'))
  end
  
  def test_superjoin_should_accept_end_argument
    assert_nothing_raised(ArgumentError) { @array.superjoin(:end => '>') }
  end

  def test_end_argument_should_append_string_after_all_others
    assert_equal('abc>', @array.superjoin(:end => '>'))
  end

  def test_superjoin_should_correctly_format_string_with_all_arguments_present
    args = {
      :start  => '<',
      :before => '*',
      :join   => '-',
      :after  => '~',
      :end    => '>'
    }
    assert_equal('<*a~-*b~-*c~>', @array.superjoin(args))
  end  
end