Agile Software Development Techniques for Daily Use.

What to Do When the Sprint Starts? 

What is TDD?

Write a test that use the methods you haven’t written yet.

Test Last

• Hard to write tests• Slow to execute tests• No tests during development• Errors leak to production• Bus factor

Test First / TDD

• Code testability for free• Fast test execution• Controlled development process• No regression• Executable Documentation

Intent

Cost of development

Time

Cost

Traditional

TDD

Your turn …

• What to do?– develop SET 

• How?– Java– TDD with JUnit–Methods: size, add, contains, remove– Storage: fixed size array

Example

Your turn …

• What to do?– develop SET 

• What’s left?–  size– contains– add– remove

TDD = Safety net

Legacy Code

Code without tests

Working with Legacy Code

• Make code testable• Capture behaviour• Refactor• Add features using TDD

Example

Your turn … 1/2

• What to do?–Write a test

• How?– Understand the code–Write a test• Minimal code change• No bug fixes

Your turn … 2/2

• What to do?– Scrap item• In stock items only• Number of scrapped

• How?– TDD– Refactoring– Bugs

Our solution

https://github.com/gsabev/ista2014

Literature

Contacts

georgi.sabev@sap.com hristo.iliev@sap.comivan.ivanov@sap.com