The document discusses using code katas and test-driven development to improve JavaScript skills, providing examples of writing tests for a parseFloat function using the Jasmine testing framework and practicing algorithms like prime factoring and the Game of Life. It emphasizes writing clean, well-tested code in pairs to internalize best practices.

1. JavaScript Code Kata
Stefan Scheidt & Bastian Söhnchen
OPITZ CONSULTING GmbH

2. Mission Märkte
Wir entwickeln gemeinsam mit allen  Branchenübergreifend
Branchen Lösungen, die dazu führen, dass  Über 600 Kunden
sich diese Organisationen besser entwickeln 29%
als ihr Wettbewerb. 29%
Handel / Logistik /
Dienstleistungen
Industrie / Versorger /
Unsere Dienstleistung erfolgt Telekommunikation
partnerschaftlich und ist auf eine langjährige 42%
Zusammenarbeit angelegt. Öffentliche Auftraggeber / Banken und
Versicherungen / Vereine und Verbände
Leistungsangebot Eckdaten
 Business IT Alignment  Gründung 1990
 Business Information Management  400 Mitarbeiter
 Business Process Management  8 Standorte
 Anwendungsentwicklung
 SOA und System-Integration
 IT-Infrastruktur-Management
© OPITZ CONSULTING GmbH 2012 Seite 2

3. Part I
Code Katas

4. What's our goal?

5. Quality

6. Value

7. Satisfaction

8. Professionalism

9. What do we need?

10. Knowledge

11. Practice ...

12. ... Practice ...

13. ... Practice!

14. Code Katas
internalize basic coding practices
to use them without thinking

15. Write clean code

16. Write tests first

17. Refactor your code

18. "Red – Green – Refactor"

19. Know your tools

20. Program in pairs

21. proper, well, fast

22. Part II
Test-Driven
JavaScript Development

23. Hello Jasmine!

24. Hello Jasmine!
describe("parseFloat", function() {
it("should return undefined for undefined", function () {
expect(util.parseFloat(undefined)).toBeUndefined();
});
it("should return 0 for empty string", function () {
expect(util.parseFloat('')).toEqual(0);
});
it("should return number for number strings", function () {
expect(util.parseFloat('1.5')).toEqual(1.5);
});
// ...
});

25. Hello Jasmine!
describe("parseFloat", function() {
it("should return undefined for undefined", function () {
expect(util.parseFloat(undefined)).toBeUndefined();
});
it("should return 0 for empty string", function () {
expect(util.parseFloat('')).toEqual(0);
});
it("should return number for number strings", function () {
expect(util.parseFloat('1.5')).toEqual(1.5);
});
// ...
});

26. Hello Jasmine!
describe("parseFloat", function() {
it("should return undefined for undefined", function () {
expect(util.parseFloat(undefined)).toBeUndefined();
});
it("should return 0 for empty string", function () {
expect(util.parseFloat('')).toEqual(0);
});
it("should return number for number strings", function () {
expect(util.parseFloat('1.5')).toEqual(1.5);
});
// ...
});

27. Hello Jasmine!
describe("parseFloat", function() {
it("should return undefined for undefined", function () {
expect(util.parseFloat(undefined)).toBeUndefined();
});
it("should return 0 for empty string", function () {
expect(util.parseFloat('')).toEqual(0);
});
it("should return number for number strings", function () {
expect(util.parseFloat('1.5')).toEqual(1.5);
});
// ...
});

28. Hello Jasmine!
expect(x).toEqual(y);
expect(x).toBe(y);
expect(x).toBeDefined();
expect(x).toBeUndefined();
expect(x).toBeTruthy();
expect(x).toBeFalsy();
...

29. Hello Jasmine!

30. Demo: Prime Factor Kata

31. Part III
Practice

32. Prime Factors

33. Word Wrap

34. Game of Life

35. Traditional archery at Japanfest
by johntrainor (http://www.flickr.com/photos/trainor/2902023575/)
Scottish Furniture Makers Exhibit
Jordanhill School D&T Dept (http://www.flickr.com/photos/designandtechnologydepartment/)
The Jewel of Simplicity
Alyssa L. Miller (http://www.flickr.com/photos/alyssafilmmaker/)
Eiqmal - Sedapnyer
emrank (http://www.flickr.com/photos/emrank/)
DSC06071
Andy G (http://www.flickr.com/photos/andyg/)
Fresh sinigang ingredients 2/365
by Nikkorz (http://www.flickr.com/photos/nikkorz/)

36. The best days are not planned
Marcus Hansson (http://www.flickr.com/photos/marcus_hansson/)
karate training
Genista (http://www.flickr.com/photos/genista/)
Orto – Vegetable Garden
Salvadonica, Chianti, Tuscany (http://www.flickr.com/photos/salvadonica/)
Making tin soldiers 3
Andrei! (http://www.flickr.com/photos/andrein/)
Roofer
Velo Steve (http://www.flickr.com/photos/juniorvelo/)
Red Light – Green Light
MoToMo (http://www.flickr.com/photos/90155419@N00/)
Craftsman
Robert S. Donovan (http://www.flickr.com/photos/booleansplit/)

37. Rallying at Dusk
Thomas Faivre-Duboz (http://www.flickr.com/photos/tfa/)
Progress
by kevin dooley (http://www.flickr.com/photos/pagedooley/)
Smiley Keyboard
~Prescott (http://www.flickr.com/photos/ppym1/)
310/365 Revision Week: Number Theory
stuartpilbrow (http://www.flickr.com/photos/stuartpilbrow/)
loose words
popofatticus (http://www.flickr.com/photos/barretthall/)
Replacement
DolfinDans (http://www.flickr.com/photos/dolfindans/)
Studies for „That‘s Life“
Ben Sisto (http://www.flickr.com/photos/bensisto/)

38. The End ...
stefan.scheidt@opitz-consulting.com
(@stefanscheidt)
bastian.soehnchen@opitz-consulting.com