The slides for Caleb Tutty's excellent talk on Test Driven Development, presented at the first Auckland Web Dev Nights meetup on the 26th April, 2012. webdevnights.github.com

1. TEST DRIVEN DEVELOPMENT
Auckland WebDev Nights Meetup - 26th April 2012
Sunday, 29 April 12

2. Who are you?
Hi, I’m Caleb Tutty - [that’s Tuh-tee]
Ruby on Rails developer working at onebigvoice
twitter: @Caleb_T
email: caleb@prettymint.co.nz
github: https://github.com/tuttinator
Feel free to pipe up with questions at any point, but there will be time at the end too.
Sunday, 29 April 12

3. What do I mean by testing?
Automated testing. Tests written by developers to check the
functionality of their application behaves as they expect it to.
(Assertions). These tests are run by a test suite.
Test broadly fall into two groups - unit tests and integration tests
Unit tests look at isolated parts of functionality, and ensuring
that each part does what you thought it should. (e.g.
Controllers and Models)
Integration tests are higher level - and aimed at the integrated
user experience. These test that everything plays nicely with
each other (e.g. the View layer interacting with Controllers
and models)
Sunday, 29 April 12

4. Cool, got it.
...so when should I test?
Sunday, 29 April 12

5. Cool, got it.
...so when should I test?
Not in production!
Before you merge into the master branch of your
source control
Actually, TATFT
Sunday, 29 April 12

6. TAFT?
Test all the f@#&ing time.*
Bryan Liles - http://www.confreaks.com/videos/496-
rubyhoedown2008-lightning-talk-tatft-test-all-the-f-in-time
* Remember this as a qualification for later:
“Quidquid latine dictum sit, altum sonatur.”
Sunday, 29 April 12

7. Really, all the time? Why?
Tests give you notifications when a change
breaks part of your app
Tests tell you where to look
Tests document your application
Tests help you work in teams
Tests mean that you can come back to a feature
later and remind you what the hell you were
doing
Sunday, 29 April 12

8. ENOUGH TALKING, NOW
SHOW ME SOMETHING COOL
Sunday, 29 April 12

9. “Quidquid latine dictum sit,
altum sonatur.”
Anything in Latin sounds
profound...
Sunday, 29 April 12

10. Too much testing?
“I get paid for code that works, not for tests, so my philosophy is to test
as little as possible to reach a given level of confidence (I suspect this
level of confidence is high compared to industry standards, but that
could just be hubris). If I don’t typically make a kind of mistake (like
setting the wrong variables in a constructor), I don’t test for it. I do tend
to make sense of test errors, so I’m extra careful when I have logic with
complicated conditionals. When coding on a team, I modify my
strategy to carefully test code that we, collectively, tend to get
wrong.” - Kent Bent, of Test First development fame
source: http://stackoverflow.com/questions/153234/how-deep-are-your-unit-tests/
153565#153565
Sunday, 29 April 12

11. Too much testing?
“When developers first discover the wonders of
test-driven development, it’s like gaining entrance
to a new and better world with less stress and
insecurity. It truly is a wonderful experience well
worth celebrating. But internalizing the benefits of
testing is only the first step to enlightenment.
Knowing what not to test is the harder part of the
lesson.” - DHH (creator of Rails)
source: http://37signals.com/svn/posts/3159-testing-like-the-tsa
Sunday, 29 April 12

12. but testing is only for Rails
devs, amirite?
Nope!
PHP
https://github.com/sebastianbergmann/phpunit/
http://symfony.com/doc/current/book/testing.html
Python
http://pytest.org/latest/
Node.js and JavaScript
http://pivotal.github.com/jasmine/
http://elegantcode.com/2011/03/07/taking-baby-steps-with-node-js-bdd-style-unit-tests-with-jasmine-node-sprinkled-with-some-should/
AS3 - I know there’s a Flex Dev in the audience
http://asunit.org/
.NET - Visual Studio has unit testing since VS 2005 -
http://msdn.microsoft.com/en-us/library/ms243147.aspx (well.. except for the free Express versions - http://greenicicleblog.com/2010/04/13/visual-studio-2010-express-no-
tests-please/ and http://www.hexsaw.org.uk/2011/01/13/once-more-on-tdd-and-microsoft-visual-studio-2010-express-edition/ )
“I’m not one who says everything should be free. Microsoft do not claim to offer a free full-blown development environment; that’s OK. But from all things that you can
leave out: why does it have to be the all abilities to run unit tests? That seems like a strange signal towards the importance of quality.”
Sunday, 29 April 12

13. is there moar?
Beyond the scope of this talk:
Factories versus Fixtures
Cucumber and BDD
JavaScript testing
Spork and Continuous Integration Servers
Sunday, 29 April 12

14. QUESTIONS?
Sunday, 29 April 12