Add support for unit testing and doctesting

New module "gpodder.unittests" that will run all
unit tests and doctests (currently only gpodder.util)
for gPodder. The tests can easily be run with a

    make unittest

in the source tree or with the following command
when gPodder is installed onto the system:

    python -m gpodder.unittests

Also added a (currently unused) helper function to
gpodder.util that already has unittests prepared.

Makefile

@@ -49,6 +49,7 @@ all: help
 
 help:
 	@echo 'make test            run gpodder in local directory'
+	@echo 'make unittest        run doctests + unittests'
 	@echo 'make mtest           run gpodder (for maemo scratchbox)'
 	@echo 'make release         create source tarball in "dist/"'
 	@echo 'make releasetest     run some tests before the release'
@@ -69,6 +70,9 @@ test:
 	@echo -ne '\033]0;gPodder console (make test)\007'
 	$(BINFILE) --local --verbose
 
+unittest:
+	PYTHONPATH=src/ python -m gpodder.unittests
+
 mtest:
 	@# in maemo scratchbox, we need this for osso/hildon
 	run-standalone.sh $(BINFILE) --local --maemo --verbose
@@ -143,7 +147,7 @@ distclean: clean
  
 ##########################################################################
 
-.PHONY: all test release releasetest install update-icons generators gen_manpage gen_graphics clean distclean messages help
+.PHONY: all test unittest release releasetest install update-icons generators gen_manpage gen_graphics clean distclean messages help
 
 ##########################################################################
 

src/gpodder/unittests.py

@@ -0,0 +1,44 @@
+# -*- coding: utf-8 -*-
+#
+# gPodder - A media aggregator and podcast client
+# Copyright (c) 2005-2009 Thomas Perl and the gPodder Team
+#
+# gPodder is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# gPodder is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+
+# Run Doctests and Unittests for gPodder modules
+# 2009-02-25 Thomas Perl <thp@gpodder.org>
+
+
+import doctest
+import unittest
+import gettext
+
+# Which package and which modules in the package should be tested?
+package = 'gpodder'
+modules = ['util']
+
+suite = unittest.TestSuite()
+
+for module in modules:
+    m = __import__('.'.join((package, module)), fromlist=[module])
+    # Emulate a globally-installed no-op gettext _() function
+    if not hasattr(m, '_'):
+        setattr(m, '_', lambda x: x)
+    suite.addTest(doctest.DocTestSuite(m))
+
+runner = unittest.TextTestRunner(verbosity=2)
+runner.run(suite)
+

src/gpodder/util.py

@@ -256,7 +256,7 @@ def file_age_to_string(days):
     ''
     >>> file_age_to_string(1)
     'one day ago'
-    >>> file_age_to_String(2)
+    >>> file_age_to_string(2)
     '2 days ago'
     """
     if days == 1:
@@ -427,6 +427,40 @@ def extension_from_mimetype(mimetype):
     """
     return mimetypes.guess_extension(mimetype) or ''
 
+
+def extension_correct_for_mimetype(extension, mimetype):
+    """
+    Check if the given filename extension (e.g. ".ogg") is a possible
+    extension for a given mimetype (e.g. "application/ogg") and return
+    a boolean value (True if it's possible, False if not). Also do
+
+    >>> extension_correct_for_mimetype('.ogg', 'application/ogg')
+    True
+    >>> extension_correct_for_mimetype('.ogv', 'video/ogg')
+    True
+    >>> extension_correct_for_mimetype('.ogg', 'audio/mpeg')
+    False
+    >>> extension_correct_for_mimetype('mp3', 'audio/mpeg')
+    Traceback (most recent call last):
+      ...
+    ValueError: "mp3" is not an extension (missing .)
+    >>> extension_correct_for_mimetype('.mp3', 'audio mpeg')
+    Traceback (most recent call last):
+      ...
+    ValueError: "audio mpeg" is not a mimetype (missing /)
+    """
+    if not '/' in mimetype:
+        raise ValueError('"%s" is not a mimetype (missing /)' % mimetype)
+    if not extension.startswith('.'):
+        raise ValueError('"%s" is not an extension (missing .)' % extension)
+
+    # Create a "default" extension from the mimetype, e.g. "application/ogg"
+    # becomes ".ogg", "audio/mpeg" becomes ".mpeg", etc...
+    default = ['.'+mimetype.split('/')[-1]]
+
+    return extension in default+mimetypes.guess_all_extensions(mimetype)
+
+
 def filename_from_url(url):
     """
     Extracts the filename and (lowercase) extension (with dot)
@@ -843,7 +877,7 @@ def format_seconds_to_hour_min_sec(seconds):
 
     >>> format_seconds_to_hour_min_sec(3834)
     '1 hour, 3 minutes and 54 seconds'
-    >>> format_seconds_to_hour_min_sec(2600)
+    >>> format_seconds_to_hour_min_sec(3600)
     '1 hour'
     >>> format_seconds_to_hour_min_sec(62)
     '1 minute and 2 seconds'