02 - Test Driven Development

Question 1

What is the traditional software development model?

Answer 1

Analysis
Specification
Design
Implementation
Testing
Operation and Maintenance

Question 2

What are the problems with the traditional software development model?

Answer 2

• Testing happens late, if at all
• Requirements decoupled from code during development
• Quality is SEP (Somebody else’s problem)
• Hard work to test, so problems are not always detected

Question 3

What is the TDD process for adding a feature to a program?

Answer 3

• Identify a feature to be implemented
• Write and run a unit test for it. This should fail
• Write the smallest/simplest bit of code which will pass the test
• Run the test
• Run all previous tests to ensure they still pass

Question 4

What does Test Driven Development prefer:

Small improvements frequently, or large improvements less often?

Answer 4

Small improvements frequently

Question 5

What are some of the characteristics of a TDD approach?

Answer 5

• Make small improvements frequently
• Always have a working system
• Incremental design
  
  • No more than required at the time
  • Don’t be afraid to modify the design

Question 6

What properties should unit tests have?

Answer 6

• Focused: They should test one thing at a time
• Fast to run
• Independent of:
  
  • Each other
  • The environment
  • Run order
• Automatic

Question 7

How does JUnit assist with Test Driven Development?

Answer 7

• Facilitates writing and running unit tests
• Has methods to check conditions: assertEquals, assertTrue, assertNull etc.
• Annotations to declare methods as tests, as well as methods to be run before every test, after every test, before all tests etc.
• Can run tests at the click of a button (with IDE integration)
• Reports any tests that fail and gives reasons why