Test-first code to create an interview question object

test_hq9f.rb

require 'minitest/autorun'
class TestHQ9F < MiniTest::Unit::TestCase
  def test_h
    # assert_output takes a block. Anything that is output inside the
    # block is captured and matched.
    assert_output "Hello World!\n" do
      h
    end
  end

  def test_99
    # When the output is really long, sometimes we want to capture it
    # and use assert_match.
    out, err = capture_io do
      HQ9F._99(99)
    end
    assert_match /99 bottles of beer on the wall,\n/, out
  end

  def test_f
    out, err = capture_io do
      hq9f = HQ9F.new
      hq9f.f(1, 100, {3 => 'Chunky', 7 => 'Bacon', 17 => 'HeartPCS'})
    end
    # If we want to reason about individual lines we need to split the
    # output into lines. String#split will split on spaces, tabs, or
    # newlines if there is no argument given.
    result = out.split()
    assert_equal '1', result.first
    assert_equal 'Chunky', result[3-1]
    assert_equal 'HeartPCS', result[17-1]
  end

  def test_each
    hq9f = HQ9F.new
    10.times do |i|
      hq9f << i
    end
    hq9f.each_with_index do |k,v|
      assert_equal k,v
    end
  end

  def test_push_pop
    hq9f = HQ9F.new
    hq9f.push_lambda lambda { puts 'PCS Rocks' }
    assert_output "PCS Rocks\n" do
      hq9f.pop_lambda
    end
  end
end