Testing Django Applications

Given at PyCon UK 20 September 2015

Video: http://pyvideo.org/pycon-uk-2015/testing-applications-for-django-cms.html

Transcript

1. PYCON UK 2015 TESTING DJANGO APPLICATIONS by Iacopo Spalletti @yakkys
2. WHO AM I? Founder and Lead developer @NephilaIt django CMS core developer django CMS installer author
3. TESTING CODE IS IMPORTANT Everyone here does it, right?
4. SELDOM IT'S ENJOYABLE Boilerplate Tests setup To mock ... or not mock?
5. CHORES OF TESTING DJANGO APPLICATIONS Fake project Fake data Fake requests Mock... Mock... Mock...
6. WITH A LITTLE HELPER... Enter djangocms-helper
7. DJANGOCMS-HELPER An addon to help writing testcases Not a replacement for unittest, nose or py.test Does not require django CMS
8. DJANGOCMS-HELPER Provides: Complete Django project Mock helpers Data setup helpers
9. DJANGOCMS-HELPER DJANGO PROJECT Bundled project with: CLI equivalent to django-admin Self configuration (almost) Sample templates
10. DJANGOCMS-HELPER MOCK HELPERS Mocking request, context, login Done in a consistent and tested way
11. DJANGOCMS-HELPER DATA SETUP HELPERS Methods to create: django CMS pages Users Images
12. HOW DO I USE IT? Write the helper file Write tests ... Enjoy
13. HOW DO I USE IT? THE HELPER FILE HELPER_SETTINGS = dict( INSTALLED_APPS=[ ... 'myapp' ] ... ) def run(): from djangocms_helper import runner runner.cms('myapp') if __name__ == '__main__': run()
14. THE HELPER FILE HOW DOES IT WORK? Add the settings needed by your application + Execute the runner
15. THE HELPER FILER HOW DOES IT WORK? 1. Merge app settings with default ones 2. Setup Django 3. Execute the Django commands
16. THE HELPER FILE SETTINGS MAGIC djangocms-helper knows a few things: South / Django migrations Django 1.8 TEMPLATE settings Depedencies and custom configurations for django CMS
17. HOW DO I USE IT? EXECUTING THE HELPER (page-meta)yakky@andalu: ~/myapp $ python cms_helper.py Creating test database for alias 'default'... ........... ------------------------------------------------------- Ran 11 tests in 8.668s OK Destroying test database for alias 'default'... Without arguments it just runs the tests
18. HOW DO I USE IT? EXECUTING THE HELPER Plus built-in commands: server: execute the bundled project so you can interact with it makemigrations: generates migrations (both south and django) compilemessages / makemessages ... any command ... (through call_command)
19. DJANGOCMS-HELPER WRITING TESTS Helpers provided by djangocms_helper.base_test.BaseTestCase
20. HOW DO I USE IT? MOCK HELPERS Generating Request object is tedious and error-prone By default no useful attributes like cookies, session, user etc
21. MOCK HELPERS REQUESTS REQUESTS djangocms-helper ships with: get_request post_request get_page_request a 'special' request for CMS frontend editor
22. MOCK HELPERS CREATING A REQUEST In [1]: request = self.get_request( page=some_page, lang='en', user=some_user, path='/en/', use_middlewares=True ) In [2]: request.COOKIES {} In [3]: request.session <django.contrib.sessions.backends.cache.SessionStore ...> In [4]: request.current_page <SimpleLazyObject: <function CurrentPageMiddleware ...>> In [5]: request.user <SimpleLazyObject: <django.contrib.auth.models.User ...>> In [6]: request._messages <django.contrib.messages.storage.fallback.FallbackStorage ...>
23. MOCK HELPERS DJANGO CMS PLUGINS Rendering django CMS plugins in tests is not straightforward Shortcuts to easily test plugin rendering BaseTestCase.get_plugin_context BaseTestCase.render_plugin
24. MOCK HELPERS DJANGO CMS PLUGINS Like this context = self.get_plugin_context(page, 'en', plugin, edit=True) # Render a single plugin rendered_1 = plugin.render_plugin(context, placeholder) # Render a whole placeholder rendered_2 = render_placeholder( placeholder, context, editable=True ) # Render the plugin - Same as rendered_1 but in one pass rendered_3 = self.render_plugin(page, 'en', plugin, edit=True)
25. MOCK HELPERS DJANGO CMS APPHOOKS Helpers to load apphooks during tests: app_page = api.create_page( 'page', 'project.html', 'en', published=True, apphook='MyApp', ) app_page.publish('en') self.reload_urlconf() Call BaseTestCase.reload_urlconf after adding an Apphook
26. MOCK HELPERS USER LOGINS [...] with self.login_user_context(self.user): # this request is made with self.user logged in self.client.get([...]) with self.login_user_context(self.user_staff): # this request is made with self.user_staff logged in self.client.get([...]) BaseTestCase.login_user_context: context manager for authenticated sessions
27. HOW DO I USE IT? CREATING DATA Lots of way of preparing test data: static fixtures custom code data generator (factory-boy et al.) Sometimes they does not fit
28. CREATING DATA DJANGOCMS-HELPER WAY django CMS is the primary target: pages titles users images
29. CREATING DATA DJANGO CMS PAGES class MyTestCase(BaseTestCase): _pages_data = ( {'en': {'title': 'page one', 'template': 'page_meta.html', 'publish': True}, 'fr_FR': {'title': 'page un', 'publish': True}, 'it': {'title': 'pagina uno', 'publish': True}}, {'en': {'title': 'page two', 'template': 'page_meta.html', 'publish': True}, 'fr_FR': {'title': 'page deux', 'publish': True}, 'it': {'title': 'pagina due', 'publish': True}}, ) ... def test_method(self): pages = self.get_pages() Built on top of django CMS API
30. CREATING DATA DJANGO CMS PAGES Supports 'complex' arguments: parent: using the slug of the parent page apphook: reloads the urlconf if any is provided
31. CREATING DATA USERS self.user = self.create_user( 'admin', 'admin@admin.com', 'admin', is_staff=True, is_superuser=True, base_cms_permissions=True, permissions=('add_something',) ) BaseTestCase.create_user knows about custom user models An admin, a staff and a normal user are provided by default in setUpClass
32. CREATING DATA IMAGES Django does not provide any quick way to create images in tests dangocms-helper does: create_image create_django_image_object create_filer_image_object
33. CREATING DATA IMAGES In [1]: self.create_image() <PIL.Image.Image image mode=RGB size=800x600 at 0x7F03382C5320> In [2]: self.create_django_image_object() <File: test_file.jpg> In [3]: self.create_filer_image_object() <Image: test_file.jpg>
34. EXAMPLES django-filer djangocms-blog djangocms-page-meta aldryn-events aldryn-newsblog
35. CHECK DOCS FOR MORE http://djangocms-helper.readthedocs.org/
36. ANY QUESTION?
37. GRAZIE!