This document discusses unit testing and provides guidance on how to implement it. It defines unit testing and explains why it is important for refactoring code with confidence, understanding code design, and creating living documentation. It provides steps for setting up, running, and verifying unit tests and recommends testing behavior rather than methods. Specific dos and don'ts are outlined such as making tests fast, fully automated, and writing informative messages. A conversation is included that emphasizes the importance of continuing to write tests.

1. Unit Testing
Ferose Khan J

2. What is Unit Testing?
User Acceptance
Testing
Integration
Testing
Unit Testing

3. Reality Check

4. Unit testing is HARD

5. Developers only write production
code

6. Never attempt UT for my code

7. Why do unit testing?
• Refactor with peace of mind
• Know when coding is done
• Understand the design
• Living documentation of the code
• Feel good on seeing those green dots

8. Steps
• Setup
• Create input
• Call the method
• Verify output
• Teardown

9. Testing Scope
• Test behavior instead of methods
• Test one layer at a time

10. Do’s
• Runs Fast
• Fully automated
• Can be executed in any order
• Produce consistent result
• Produce atomic result
• Write informative message

11. Don’ts
• Conditional coding in tests
• Catch unexpected exceptions in tests
• Loops inside tests
• Testing related logic in production code

13. Conversation master programmer & pupil:
Pupil: “When can I stop writing tests?”
Master:“When you stop writing code.”
Pupil:“When do I stop writing code?”
Master:“When you become a manager.”
(The pupil trembled)
Pupil: “When do I become a manager?”
Master: “When you stop writing tests.”
The pupil rushed to write some tests.
He left skid marks.

14. “Unit testing is part of the
design process and not
part of testing process”