2012-01-17T21:54:19-08:00 http://davedash.com/ Dave Dash dd+atom1@davedash.com 2011-08-10T00:00:00-07:00 http://davedash.com/2011/08/10/djangocon-testing-tutorial <div class="side"> <img src="/static/images/2011/08/10/djangocon.png" width="287" height="184" alt="DjangoCon 2011" /> </div> <p>If you want to learn all you can about testing anything in your Django App, see <a href="http://djangocon.us/schedule/presentations/30/">my tutorial</a> at <a href="http://djangocon.us/">DjangoCon</a>. It's on September 5th, it'll be 3 hours long and so far with seven sign ups it will be very hands-on.</p> <p>Here's what I think I will cover, but I may change this depending on what the audience wants:</p> <ul> <li>Testing issues <ul> <li>ask people to fill out etherpad with issues they've run into</li> <li>ask someone to rank them in order of complexity</li> </ul> </li> <li>List an outline of topics <ul> <li>post them on etherpad</li> <li>have people + them if they are interested</li> </ul> </li> <li>Testing overview <ul> <li>We started in late 2009 early 2010</li> <li>Our largest project has 2500 tests</li> <li>Our next largest has 1100</li> <li>We have pretty good coverage</li> </ul> </li> <li>How testing works in Django <ul> <li>I'm not 100% sure on this</li> <li>Test runner setups up a new database</li> <li>Test runner finds and runs tests</li> <li>Tests run class setup</li> <li>Test runs each test in a test case <ul> <li>Load fixtures</li> <li>Tests run setup</li> <li>Tests runs the test</li> <li>Tests runs teardown</li> </ul> </li> <li>Tests run class Teardown</li> <li>You get an F if you're bad and a . if your not.</li> <li>Now that you know it, you can hack it.</li> </ul> </li> <li>How we've hacked testing <ul> <li>2500 tests is a lot</li> <li>We no longer recreate the database when you run the test suite</li> <li>In each test case we just load the fixtures once.</li> <li>We rearrange the tests so things with the same fixture set run together</li> </ul> </li> <li>Testing tools that we use at Mozilla <ul> <li>nose/django_nose</li> <li>nose plugins <ul> <li>nicedots</li> <li>progressive</li> </ul> </li> <li>coverage <ul> <li>git + whatchangedpy</li> </ul> </li> </ul> </li> <li>Testing everything, no excuses <ul> <li>100% Coverage isn't important</li> <li>80% is nice</li> <li>Good coverage on tricky things is important</li> <li>Some coverage on everything is important</li> <li>External</li> <li>If you start depending on APIs, Search or different tools you need to be able to test for them.</li> <li>Writing these test cases will take less time than this tutorial</li> <li>It will save you so much headache in the future.</li> <li>The same headaches you save yourself by writing "normal" tests</li> <li>Mock easy things <ul> <li>use a decorator on any test/view that might use redis</li> <li>if redis isn't setup, use the mock client</li> <li>mock client doesn't support everything, <ul> <li>just what I need to get my tests running -</li> <li>feel free to extend it if you use it</li> </ul> </li> <li>Testing Redis</li> </ul> </li> <li>Setup/Teardown for complicated tools <ul> <li>Good for search and APIs</li> <li>Raise SkipTest (nose) if the developer doesn't want to run these tests</li> <li>Non realtime tools <ul> <li>Testing Sphinx search</li> <li>SetupClass <ul> <li>load fixtures</li> <li>run indexer</li> <li>run server</li> </ul> </li> <li>Sphinx server now available for all tests in your test case</li> <li>Teardown <ul> <li>stop server</li> </ul> </li> </ul> </li> <li>Real time tools <ul> <li>Nicer, data can be added in post_save signals or elsewhere in your app</li> <li>Testing LDAP <ul> <li>Setup <ul> <li>Remove LDAP files</li> <li>Load an ldif</li> <li>Start slapd</li> </ul> </li> <li>Your code can now touch LDAP</li> </ul> </li> <li>Testing ElasticSearch <ul> <li>We leave ES running all the time.</li> <li>Setup <ul> <li>Checks for ES support or SkipTest</li> <li>Deletes index</li> <li>Creates index</li> </ul> </li> <li>You can now read/write to ES</li> <li>Teardown <ul> <li>Delete's index</li> </ul> </li> </ul> </li> </ul> </li> </ul> </li> <li>Fixtures <ul> <li>Fixture Magic</li> <li>Model Maker</li> </ul> </li> <li>pitfalls <ul> <li>dates</li> <li>using PDB</li> </ul> </li> </ul> </li> </ul> 2009-09-15T00:00:00-07:00 http://davedash.com/2009/09/15/djangocon-wrapup <p>I went to <a href="http://djangocon.org/">DjangoCon</a> this past week for work. Django is one of my favorite frameworks. I dropped PHP and the symfony framework to learn python and Django and I haven't looked back. I think for Mozilla's webdev team it would be the framework of choice. We have 100s of sites in many frameworks, but not a lot of resuability. Django apps are built to built to be reusable. If you build correctly you don't have to refactor, it's already done.<!--more--></p> <p>Here's a collection of notes I collected through the conference.</p> <h3>Day one</h3> <h4>Keynote - Avi Bryant</h4> <blockquote><p>Frameworks lock us into RDBMS = bad</p></blockquote> <p>This keynote mentioned the limits of modern frameworks and modern web development. Essentially frameworks are great for getting started, but as a site grows, the framework gets replaced little by little. Sometimes it can get in the way - such as with limitation of database choices.</p> <h4>UR doing it wrong - James Bennet</h4> <p>James outlined a few key problems that many Django developers run into:</p> <ul> <li><p>learning python as you go</p> <ul> <li> doesn't work unless you know some programming upfront</li> <li> do the python tutorial</li> <li> read python in a nutshell or dive into python</li> </ul> </li> <li><p>Things you should know:</p> <ul> <li>subclasses</li> <li>super()</li> <li>slides went too fast... hopefully they'll be posted</li> </ul> </li> </ul> <p>All in all RTFM for python and Django :)</p> <p>Learn about other py packages... like twisted. If Twisted Matrix was implemented in Ruby it would be advertised as the second coming of Christ.</p> <p>Bennet's Django App review smoketests:</p> <ul> <li>installable via pip, easy_install or setup.py <ul> <li>read distutils-guide</li> <li>stay away from setuptools</li> </ul> </li> <li>have a README</li> <li>INSTALL file list deps</li> <li>Write DOCUMENTATION <ul> <li>use sphinx.pocoo.org</li> <li>store it in your package <em>and</em> upload package docs</li> </ul> </li> <li>LICENSE (most Django apps use BSD)</li> <li>Write unit tests</li> <li>django-lint - to look over code (like pep8.py)</li> </ul> <p>pro-django is a decent book, but not written by Bennet.</p> <h4>Testing - Eric Holscher</h4> <ul> <li>Django 1.1 encourages you to test by auto-creating tests.py.</li> <li>Support for: <ul> <li>Unittests</li> <li>Doctest</li> <li>Tests done in a db transacation</li> </ul> </li> <li>Test Driven Documentation (TDD + DDD)</li> <li>Doctest <ul> <li>easy</li> <li>can't use PDB</li> <li>Hides certain failures</li> </ul> </li> <li>Unittests via Django TestCase <ul> <li>XUnit</li> <li>setup/Teardown</li> <li>adds db fixtures</li> <li>assertions</li> <li>mail testing/inbox testing</li> <li>url testing</li> </ul> </li> <li>TestCase <ul> <li>Browserless Request/Response testing</li> <li>Similar to sfBrowser in symfony</li> </ul> </li> <li>Google Summer of Code (for Django 1.2) <ul> <li>Coverage reports!</li> </ul> </li> <li>I need to learn PDB</li> </ul> <h4>Deploying Django -</h4> <p>Run mod_wsgi in daemon mode.</p> <h3>Day 2</h3> <h4><a href="http://blog.ianbicking.org/2009/09/10/a-new-self-definition-for-foss/">Keynote - Ian Bicking</a></h4> <p>GNU Manifest:</p> <blockquote><p> I consider that the golden rule requires that if I like a program I must share it with other people who like it. Software sellers want to divide the users and conquer them, making each user agree not to share with others. I refuse to break solidarity with other users in this way. I cannot in good conscience sign a nondisclosure agreement or a software license agreement. ...</p> <p>So that I can continue to use computers without dishonor, I have decided to put together a sufficient body of free software so that I will be able to get along without any software that is not free.</p></blockquote> <ul> <li>GNU manifesto was the idea of sharing software amongst friends</li> <li>GNU has purpose - BSD, etc is just a rule - free to share</li> <li>Free is not just the absense of copyright</li> <li>Free is not a reaction to existing rules, but a golden rule</li> <li>Not just a fight against MS</li> <li>Need to find morality (the why) within the practical (the law, or what you can do)</li> <li>Open sourcing closed source code isn't building open source</li> <li>This might apply to Mozilla... as webkit has taken off more than Gecko.</li> <li>Open source is person to person not company to company - despite sponsorship.</li> </ul> <h3>Using Django in Non-standard ways - Eric Florenzano</h3> <ul> <li>Django loosely coupled</li> <li>Replace templating with Jinja 2</li> <li>Copy Django methods into djangoext to easily customize Django behavior</li> <li>Not using django.contrib.auth <ul> <li>reasons: writing a fb app - no auth needed</li> <li>no shoehorning needed - saves time - less overhead</li> </ul> </li> <li>skip the orm? <ul> <li>legacy dbs</li> <li>non standard or db (or non-relational database)</li> <li>no database</li> </ul> </li> <li>wsgi middleware has some cool shit <ul> <li>repose.bitblt: autoscales images</li> <li>repose.squeeze: will concat js/css on the fly based on statistical analysis</li> </ul> </li> <li>non standard Django based apps <ul> <li>YARDBird - IRCBot framework</li> <li>djng micro framework</li> <li>Jngo- singlefile cms</li> </ul> </li> <li>using admin in a nonstandard way is hard/impossible coupled with ORM and auth</li> </ul> <h4>Real-time web and other Buzzwords - Chris Wanstrath</h4> <ul> <li>more than just getting your rss feeds faster</li> <li>push vs. pull</li> <li>1 persisting connection vs polling</li> <li>comet/flash-xml/or html5 web socket</li> <li>orbitted - open source python comet server</li> <li>zeddicus - does the business logic</li> <li>orbitted has its own js libs - its a simple port/socket thing for your server code to deal with - not request/response.</li> <li>all connections are persisting browser/orbitted orbitted/zeddicus</li> <li>You can even use orbitted to connect straight to IRC and write a client in JS</li> <li>Jetty also is good for comet</li> </ul> <p>Also: * see webhooks * see pubsubhubub</p> <h4><a href="http://www.slideshare.net/nowells/djangocon-09-presentation-pluggable-applications">Pluggable, Reusable Django Apps: A Use Case and Proposed Solution</a> - Shawn Rider and Nowell Strite</h4> <ul> <li>PBS moved from perl to django - build a lot of reusable apps</li> <li>convincing your superiors <ul> <li>need a good story -</li> <li>existing base of python helped</li> <li>With Django easy to do things right without doing things slow</li> <li>be really good...</li> </ul> </li> <li>built a lot of apps to be very reusable, and pluggable based on requirements PBS had</li> </ul> <h3>Day 3</h3> <h4><a href="http://www.slideshare.net/twleung/djangocon-2009-keynote">Keynote</a> - Ted Leung - Sun</h4> <ul> <li>Django jobs are a growing market</li> <li>Preferred by startups</li> <li>Bespin/wave - cool</li> <li>APIs are big... still</li> <li>Physically impossible to create purely server-side interactions that are usable enough - rely on rest/comet/ajax/etc to bridge gap</li> </ul> <h4><a href="http://immike.net/files/scaling_django_dc09.pdf">Scaling Django</a> Mike Malone</h4> <ul> <li>MM from Pownce (now sixapart)</li> <li>Slides started out as "Building Scalable Web Applications"</li> <li>Django didn't get in the way too much when it came to scaling</li> <li>Django had tons of caching support</li> <li>Cached objects by hand (memcached) and object ID lists</li> <li>Use memache for sessions too</li> <li>use signals to signal cache invalidation</li> <li>race conditions...</li> <li>Queue shit... gearman, rabbit mq, etc.</li> <li>Memecached incr/decr operators are awesome</li> <li>See gh/mmalone/django-caching</li> <li>See gh:.../django-multidb</li> <li>to combat slavelag use a memcache key to alternate between master or slave</li> </ul> <h4><a href="http://heisel.org/blog/2009/09/11/gearman/">Gearman - working later</a> - Chris Heisel</h4> <ul> <li>Gearman - a work later alt to rabbit mq</li> <li>Makes the most sense for something like cesium, with a bazillion worker <strike>bees</strike> foxes feeding off a single queue</li> </ul> <p>Also at the con, I talked to someone about rebuilding large apps... and they took a PHP app and used URL rewriting to and a lot of PHP/Python glue code to build a seamless transitory app. The rule is, all new functionality was done up in python while the old app was in maintenance mode.</p> <p>More talks <a href="http://djangocon.pbworks.com/Slides">here</a>!</p>