『メタプログラミングRuby 1.2.2 オープンクラスの問題点』でRubyのテストのやり方って？（おまけ：Pythonの場合）

Ruby の場合

Ruby1.9.3

replace.rb

def replace(array, from, to)
  array.each_with_index do |e, i|
    array[i] = to if e == from
  end
end

test_replace.rb

require 'minitest/unit'
load 'replace.rb'

MiniTest::Unit.autorun

class ReplaceTest < MiniTest::Unit::TestCase
  def test_replace
    book_topics = ['html', 'java', 'css']
    replace(book_topics, 'java', 'ruby')
    expected = ['html', 'ruby', 'css']
    assert_equal expected, book_topics
  end
end

shell

$ ruby test_replace.rb -v
Run options: -v --seed 60141

# Running tests:

ReplaceTest#test_replace = 0.00 s = .


Finished tests in 0.000441s, 2267.5737 tests/s, 2267.5737 assertions/s.

1 tests, 1 assertions, 0 failures, 0 errors, 0 skips

これでよいのかな？

library minitest/unit

Pythonの場合

お手軽簡単にdoctestで
Python2.7

hoge.py

def rep(array, from_str, to_str):
    """
    >>> book_topics = ['html', 'java', 'css']
    >>> rep(book_topics, 'java', 'ruby')
    >>> expected = ['html', 'ruby', 'css']
    >>> assert expected == book_topics
    """
    for i, e in enumerate(array):
        if e == from_str:
            array[i] = to_str


if __name__ == '__main__':
    import doctest
    doctest.testmod()

shell

$ python hoge.py -v
Trying:
    book_topics = ['html', 'java', 'css']
Expecting nothing
ok
Trying:
    rep(book_topics, 'java', 'ruby')
Expecting nothing
ok
Trying:
    expected = ['html', 'ruby', 'css']
Expecting nothing
ok
Trying:
    assert expected == book_topics
Expecting nothing
ok
1 items had no tests:
    __main__
1 items passed all tests:
   4 tests in __main__.rep
4 tests in 2 items.
4 passed and 0 failed.
Test passed.