This document discusses test-driven development (TDD) and its benefits. It advocates following a process of writing tests before code to ensure code quality and prevent bugs. TDD involves writing a test, seeing it fail, writing the minimum code to pass the test, and refactoring code as needed. While initially time-consuming, TDD can save time in the long run by producing well-designed, modular code that is documented by tests and catches errors early. The document provides examples of TDD and cautions that intelligence alone is not enough - following a disciplined process is important for success.

1. Test-DrivenDevelopment
Write better code
in less time
Md. Hasan Basri (Angel)
Full Stack Java SE/EE Engineer | Life Long Learner
www.linkedin.com/in/pothiq/
pothiq@gmail.com

2. INTELLIGENCE
IS
A LIABILITY!

3. SMART PEOPLE
Can make progress …
… without process
(This is NOT a good thing)

4. Washing hands
and organizing
surgical tools
wastes a lot of
time. I could
help more
patients if I just
dove in.

5. We know how
skyscrapers
work.
Just give us
some bricks
and we'll get
started.

6. PROFESSIONALS:
• Design, plan and prepare first
• … do the work
• This produces better results faster

7. PROCESS IS THE
DIFFERENCE BETWEEN:
Surgery … and …
Cutting
people
open

8. PROCESS IS THE
DIFFERENCE BETWEEN:
Engineering … and … Tinkering

9. PROCESS IS THE
DIFFERENCE BETWEEN:
Software
Engineering
… and … Programming

10. If I take the
Time to write
tests,
I won't finish
this feature
on time.
(Don’t be this guy)

11. I'll go back
and write
the tests
afterwards.
(Don’t be this guy either)
(Too Late!)

12. SOFTWARE PROCESS:
• Architecture
• Conventions & Standards
• Version Control
• Coordination (agile, etc.)
• Test-driven development

14. TESTS PROVIDE:
• Documentation of code
• Catch feature errors
• Long-term time savings
But test are just a tool, not a process.

15. TDD DEFINED:
• Decide what the code will do
• Write a test that will pass the code dost that
thing
• Run the test, see it fail
• Write the code
• Run the test, see it pass

16. TDD PROVIDES:
• Design and plan before you code
• Document your design
• Proof that code implements design
• Encourages design of testable code

17. TESTABLE CODE:
Looks a lot like good code!
• Modular
• Decoupled design
• Methods of limited scope
• etc.

18. RESULTS:
Better code in LESS TIME.

19. CAVEAT:
You will have to do this for a while
before you will be faster.

20. CAVEAT #2:
Intelligence is an Asset!

21. USE JUDGEMENT:
• Some things are too hard to test
• Some tests are too trivial to be useful
• Over testing is possible
• Exploratory coding w/o tests is OK!

22. RECAP

24. Variety of Options

25. TDD Cycle

26. Test Cases Acceptance Criteria

27. Time when bug is found …

28. Acceptance Test Driven Development

29. Tools For TDD/ATDD

30. LET’S DO SOME EXERCISE

31. jUnit Sample
• We will try to satisfy following conditions.
Condition for Password acceptance:
1. The password should be between 5 to 10 characters.
.

32. jUnit Sample
To run test, we create class PasswordValidator ()

33. jUnit Sample
We will run above class TestPassword ();