More than XP. More than one day.

Summary

This hands-on tutorial teaches Test-Driven Development and Mock Objects using the JUnit and jMock 2 libraries. We will cover: What is Test-Driven Development? Why is it so widely used in Agile projects? What are Mock Objects and where do they fit into the TDD process? How are tests and Mock Objects used to drive good object-oriented design.

We will touch on: What should, and should not, be mocked? How do you write flexible tests that do not break when you make unrelated changes to the code? How do you use the tests to identify issues with the design and how do you fix those issues?

Programme

We will start by presenting an overview of TDD that addresses the following questions:

• What is Test-Driven Development?
• Why is it so widely used in Agile projects?
• What are Mock Objects and where do they fit into the TDD process?
• How are tests and Mock Objects used to drive good object-oriented design

The presentation will conclude by describing the scenario that we will use for the pair programming exercise to come.

We will then introduce the jMock 2 API through a live demonstration, writing the first test of the exercise and then just enough code to make it pass.

The participants will then work in pairs to implement the first test for themselves and continue with the exercise. The exercise will be run in iterations. After each iteration the participants will share the lessons they learned with the group and we will present more detailed explanations of the issues raised. The exercise and discussions will answer the following questions:

• What should, and should not, be mocked?
• How do you write flexible tests that do not break when you make unrelated changes to the code?
• How do you use the tests to identify issues with the design and how do you fix those issues?

We will wrap up the session with a further presentation reiterating the lessons learned and looking at them in more detail, with good and bad code examples.