Test Driven Development

• TDD is a powerful way to produce well designed code with fewer defects
• The best way to write a code is to shape it from the beginning with tests
• Fewer defects = lesser debugging, more confidence, better design & higher productivity

Step A : Test First Design (TFD)

• Create a Test Case and create a code small enough to fail the test
• Next, run the test to ensure it fails
• Update the functional code to make it pass the test case
• If it fails update/fix the code to pass the tests

Step B : Refactoring

• Refactor any duplication out of design turning TFD into TDD

                                                TDD = TFD + Refactoring

A TDD team (SDU - Software Development Unit) has many responsibilities and is characterized by the following attributes:

• An exhaustive suite of test scripts are maintained in a centralized test management repository as development progresses
• No code goes into production unless it is associated with tests and test results
• The test is written before the code first and for the smallest possible unit of functionality
• A test case is passed along with the generated code
• The tests determine what code is written
• Users are involved in writing test scripts and they thus become the development specifications
• TDD tests are by definition unit level tests that exercise code across object boundaries in many cases
• Developers test method by method of each class as it is constructed
• All test cases that can be automated should be, using a Unit Testing Framework (UTF) that helps the team in creating, executing and managing the process – this also aids regression testing that must be performed