This document discusses test-driven development (TDD). It defines TDD as an evolutionary approach where tests are written before code to verify functionality. The TDD cycle involves writing a test, making it pass by writing code, and refactoring code and tests. Advantages include more consistent testing, clarified interfaces and behavior, and confidence to refactor. An example walks through writing tests for password requirements, developing code to pass tests, and refactoring code and tests.

1. Test Driven Development
Comp 645
Topics in Software Development
Presented by: Rashmi Srivastava
Franklin University, Summer 2018

2. Agenda
 What is TDD & TDD Cycle
 Advantages
 How to perform TDD Test
 Example Test Driven Development
 Summary
 References

3. What is TDD
 Test-driven development (TDD), is an new age
evolutionary approach to development which
emphasizes test-first development.
 It starts with designing and developing tests for every
small functionality of an application.
 Key Point: The test is written first, imagining the code
to be tested is written.
 TDD cycle
 Write a test
 Make it run
 Change code to make it right i.e. Refactor
 Repeat process

4. Advantages Includes
 The unit tests actually get written
 Programmer satisfaction leading to more consistent test writing
 Clarification of detailed interface and behavior
 Provable, repeatable, automated verification
 The confidence to change things

5. How to perform TDD Test
 see the rhythm of test-driven
development
 Add a test.
 Run all tests and see if any new
test fails.
 Write some code.
 Run tests and Refactor code.
 Repeat.

6. Example Test Driven
Development
 Requirements
 passwords meet the following
criteria
 Between 6 and 10 characters
long
 Contain at least one digit
 Contain at least one upper
case letter

7. Write the code

8. TDD Example: Refactoring #1

9. TDD Example: Refactoring #2

10. Final code

11. Final Test class

12. Summary  What is TDD & its Advantages
 Example Test Driven Development

13. References
 http://agiledata.org/essays/tdd.html
 Larman, C. (2004). Applying UML and patterns: An introduction to object-
oriented analysis and design and iterative development. (3rd).