Test Driven Development - Phương pháp phát triển phần mềm theo hướng viết test trước. Áp dụng TDD sẽ đem lại cho bạn thiết kế phần mềm trong sáng hơn và quản lý được chất lượng từng dòng code của mình viết ra. Bài trình bày của bạn Lê Anh tại Meetup của Ha Noi .NET Group. Chi tiết vui lòng xem tại: http://tungnt.net

1. Test Driven
Development
LE ANH
APOLLO13.VN

2. Outline
 Overview about TDD
 Why use TDD ?
 How to do ?
 TDD by Example
 Common mistakes in TDD
 When we use TDD ?
 Q&A

3. Overview about TDD
TDD stand for Test Driven Development (Test Driven Design)

4. Overview about TDD
Regardless of the programming language

5. Overview about TDD
TDD is a strong methodology
Without TDD TDD

6. Why use TDD ?
Clean code

7. Why use TDD ?
Without TDD Prevent bugs by TDD

8. Why use TDD ?
Design document

9. Why use TDD ?
Maintainable, flexible, easily extensible

10. Why use TDD ?
TDD change your mindset a bout programming & testing. You can
become a better programmer

11. How to do TDD?
Do it in baby stepsIs TDD Difficult ?

12. How to do TDD?
Mantra of TDD is “Red/Green/Refactor”

13. How to do TDD?
Red text is 3C rule. They help raise your idea

14. How to do TDD?
 We have a user story, use 3C rule to make your idea (baby
requirement)
Allow user input a
string to set the
display name when
he login. Max length
of string is 125
characters

15. How to do TDD?
 String can contain special characters ?
 What kind of special characters (!@#$%^&...) ?
 String can contain space ?
 String can contain number ?
 Min length of string ?
 String can not contain select, delete, update
because of SQL injection
 String can be duplicate ?
Note : Don’t think the requirement is very simple therefore we don’t
need to confirm with PO. Confirmation is a way to prevent bugs

16. TDD by examples
 Example 1: write a method that reverse last 2
characters of string.
 If null  return null, if empty  return empty, if
length of string equal 1  return itself
 Ex: “A”  “A”, “” “”, null  null, “AB” “BA”,
“RAIN”  “RANI”

17. TDD by examples
 Create first test case

18. TDD by examples
 Can not compile because StringHelper class is not created

19. TDD by examples
 After StringHelper class is created, run ALL TEST CASE to see
they(or one of them) fail

20. TDD by examples
 Make a litte change to pass this test cases
Question : Who has a better implementation ?

21. TDD by examples
 Run ALL TEST CASES to see they pass

22. TDD by examples
 We have just finished a baby step of TDD cycle. Repeat it
again.

23. TDD by examples
 After StringHelper class is created, run ALL TEST CASE to see
they(or one of them) fail

24. TDD by examples
 Refactor code to pass this test case

25. TDD by examples
 Run all test cases to see they pass

26. TDD by examples
 Refactor test code if necessary

27. TDD by examples
 Add new test case

28. TDD by examples
 After StringHelper class is created, run ALL TEST CASE to see
they(or one of them) fail

29. TDD by examples
 Refractor code to pass the test case

30. TDD by examples
 Run all test cases to see they pass

31. TDD by examples
 Add new test case, this test case will be pass without any
changes

32. TDD by examples
 Add new test case, this test case will be fail

33. TDD by examples
 Refactor code

34. TDD by examples
 Run all test cases, if they pass and you don’t have any test
case. The TDD cycle is completed. Refactor code if necessary

35. TDD by examples
Example 2: Refer the below link
http://technologyconversations.com/2013/12/20/test-driven-
development-tdd-example-walkthrough/

36. Common mistakes in TDD

37. Summary

38. Q&A
 What is the position of tester in agile test (TDD) ?
 What is BDD/ATDD ?
 What are the skill of tester, developer in scrum ?
 When we use TDD ?
 Is TDD dead ?
 Some questions from audiences…..