Notes from my test-heavy track of RailsConf 2007 sessions, as presented to the SouthBend.rb ruby and rails user group on May 29, 2007

1. Selected Sessions from
RailsConf 2007
Jerry Richardson, jerry@jerryr.com
Chief Technologist, iBlinkink

2. Clean Code
• incremental improvement
• always check code in better than you checked it out
• never let the sun set on bad code
• test first => quot;test obsessedquot;
• provides the necessary flexibility

3. Robert Martin
“I am not allowed to make a
change that breaks the
system. Every tiny change I
make will keep that system
working.”

4. Let’s Refactor
• Principle of least surprise
• tiny steps => change each variable type, then run the
tests
• shrink the granularity of your development
• create a barrier between things that change and things
that don't

5. Is it worth it?
• crafting good solutions
• clean it up as soon as it gets messy => the dinner
parable: get up and walk away from the dinner table or
keep your dishes clean all the time
• bad schedules, requirements, team dynamics can all be
fixed but bad code rots, ferments and becomes an
inexorable weight that drags the team down.

6. Professional Behavior
• The quot;Green Bandquot;
• Professionals write their tests first
• Professionals keep their code clean
• Professionals know that the only way to go fast is to go
well.
• making things a little bit nicer => the check-in rule

7. Doing REST Right
Recognize rest principles in what you're
already doing. Apply them to your
whole process.
Orthodoxy (right teaching, right beliefs,
right thoughts) versus Orthopraxy
(right practice)

8. Orthodoxy
• Roy Fielding's Thesis defined REST (Representational
State Transfer)
• All models are wrong but some are useful. - George
Box
• Leaky Abstractions
• Diagrams are wrong but useful in representing
complex, real-world systems. Same thing with
abstractions.

9. REST isn’t...
• Pretty URLs
• CRUD
• respond_to
• map.resources
• a protocol - http
• an architecture

10. REST is...
• the architectural style of the web
• Roy Fielding's Hierarchy
• Abstract => Communication Theory
• REST
• Web Architecture
• Concrete => Implementation

11. REST is...
• A resource is anything that can be named
• A resource is an object with a couple of contraints -
can only implement a very small number of methods,
same for all resources
• you don't access a resource -- you access a
representation of it. (respond_to with format.xml,
format.txt, etc.)

12. Orthopraxy
• Identification - URL
• Interaction (Method or Verb)
• Safety - has no side effects, incurs no obligations (get
is the only method that is safe by definition)
• idempotent -- applying a function once returns the
same value as applying it multiple times (get, put and
delete)

13. Post
• post is neither safe nor idempotent => reserve it for
when you need it

14. Content, Body of Request
• REST pushes all of the complexity into content, out of
identification and interaction
• messages should be use standards and be self-
descriptive, like html
• look for content types that map to your application
domain - instead of to_xml, use an established type for
users => do vcard instead of your arbitrary user xml

15. Adding Tests to
Legacy Rails Apps
Most first-time Rails apps are built
before a developer understands their
importance. Testing is painful in many
frameworks and ignored when many
people switch to using rails.

16. Starting
• Don't do it all at once. It won't work.
• first, run rake
• mysqladmin -u root create appname_test
• Use Migrations
• Scaffolding is broken => those tests don't work.

17. One Step at a Time
• find a bug, write a test
• refactor a method, write a test
• treat each method as a box - don't get pulled in to
testing everything
• test one thing at a time
• Test: what goes in? what comes out? (returning
something in the method)

18. Rake or Direct Testing
• rake or direct testing
• rake testing: rake test:uncommitted
• direct: ruby test_file.rb -n test_name to run one test
in a specific file

19. Build Tests from Logs
• Parameters then reproduce actual requests.

20. What To Test
• right response code
• correct template
• variable assignment
• assignment of desired object

21. Me.
Questions?

22. Image Credits
• DHH
http://flickr.com/photos/x180/503574487/
• Robert Martin
http://flickr.com/photos/x180/503608084/
• Scott Raymond
http://flickr.com/photos/keeg/511239686/
• Evan (Rabble) Henshaw-Plath
http://flickr.com/photos/x180/474128166/
• Me
http://flickr.com/photos/jackdanger/502998700/