The document discusses best practices for writing JavaScript code for large web applications. It recommends creating abstractions for business logic, presentation logic, and integration points like HTTP requests and DOM manipulation. This allows writing unit tests for each component in isolation. The talk also suggests keeping presentation logic classes "skinny" and favoring interaction tests over integration tests. Tools mentioned include jQuery, JSTestDriver, Ewloe and JavaScriptLint.

1. The secret art of Agile
Javascripting
Luca Grulla
Italian Agile Day,
Genova, 19/11/10

2. Our background
Large public facing websites
Significant javascript codebase
with complex DOM interaction
Heavy use of Ajax
Large amount of business logic
Long life expectancy

3. Disclaimer
This presentation is technology agnostic
Each tool used is replaceable
It is not about how to use jQuery

4. Technology Stack
• JQuery
• JSTestDriver
• Ewloe
• JavascriptLint

5. It used to be so
simple…

6. Rich clients

7. We want unit tests

8. Scenario
Login form
Need to validate user credentials
Need to execute a server call via ajax POST
Based on the result we need to show a
welcome or an error message

13. So what is wrong
with this code ?

15. We want to test it!

16. Domain abstraction

17. Abstraction around
integration points

18. HTTP
DOM
Presentation
Logic
Business Logic

26. Our approach
Javascript is a first class language
create abstractions:
business logic
presentation logic
integrations
…but not limited to a specific pattern !!
Keep your presentation logic class as skinny as
possible in order to express intents
Favour interaction tests over integration tests

27. Tools Considerations
….whatever you like but has to be pluggable
in your Continuous Integration !!

28. Questions ?

29. Thank You !
Luca Grulla
luca.grulla@thoughtworks.com
http://www.lucagrulla.it/blog
http://www.github.com/lucagrulla

30. References
Ewloe
http://github.com/gurrie/ewloe