Basic TDD style unit testing with PyUnit

testee.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""Testee module

This script just writes 'Hello, world.' in your language. This is my study case
of unit testing for test-driven development.
"""

import locale

__author__ = 'Yu I.'
__license__ = 'Public domain'
__version__ = '0.1'

messages = {'en': 'Hello, world.',
            'es': '¡Hola, mundo.',
            'ja': 'こんにちは、世界。'}

def get_language():
    """Return default language code like 'en'"""

    defaultlocale = locale.getdefaultlocale()
    language = defaultlocale[0][0:2]

    return language

def get_message():
    """Return localized message"""

    language = get_language()

    if not messages.has_key(language):
        language = 'en'

    return messages[language]

if __name__ == '__main__':
    print get_message()

tester.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""Tester module

This script just writes 'Hello, world.' in your language. This is my study case
of unit testing for test-driven development.
"""

import locale
import unittest
import testee

__author__ = 'Yu I.'
__license__ = 'Public domain'
__version__ = '0.1'

class LanguageDetectorTestCase(unittest.TestCase):
    """Detect language"""

    def test_get_language(self):
        """Return default language code like 'en'"""

        defaultlocale = locale.getdefaultlocale()
        language = defaultlocale[0][0:2]

        self.assertTrue(isinstance(language, str),
                        'Value should be string')
        self.assertEqual(len(language),
                         2,
                         'Value should be alphabetical 2 letters')

class MessageWriterTestCase(unittest.TestCase):
    """Write message"""

    def setUp(self):
        self.messages = {'es': 'Hello, world.',
                         'es': '¡Hola, mundo.',
                         'ja': 'こんにちは、世界。'}

    def test_get_message(self):
        """Return localized message"""

        language = testee.get_language()

        if not self.messages.has_key(language):
            language = 'ja'

        self.assertTrue(isinstance(self.messages[language], str),
                        'Value should be string')

def suite():
    """Create Test Suite"""

    testsuite = unittest.TestSuite()

    testsuite.addTest(LanguageDetectorTestCase('test_get_language'))
    testsuite.addTest(MessageWriterTestCase('test_get_message'))
    return testsuite

if __name__ == '__main__':
    # Run Test Runner
    unittest.TextTestRunner(verbosity=2).run(suite())