Test Driven Development (Workshop)

Overview

• Ability to take the TDD approach to software development
• Understanding of the key techniques and strategies of TDD, and principles of refactoring code
• Ability to write unit tests in JUnit versions 3 and 4
• Ability to use mock objects in unit tests

Unit tests and the xUnit framework. JUnit overview. The TestCase and Assert classes. Developing a JUnit 3 test and test suite for a class. Java 5 features used in JUnit 4. JUnit 4 versions of tests and test suites. JUnit and ant.

Motivation for using Mock Objects. Stubs and Mocks. Worked example. EasyMock argument matchers. Mocking and Static methods. When to use Mock Objects. Drawbacks of Mock Objects

Traditional Development (Code-Test-Refactor). Extreme Programming. Test Driven Development. Benefits of TDD. TDD Process: Worked Example. TDD Strategies. Unit Testing Best Practices. Exception tests. Performance tests

"Code Smells". Benefits of Refactoring Code. Important Refactorings. Testing Patterns. Testing Heuristics. Coverage

This course is designed to bring about a fundamental change to the way developers go about their day-to-day business of writing software code. Instead of thinking about unit tests as at best an afterthought, having already written the application code, the course aims to turn this practice on its head, and get programmers to write tests before the code to be tested.

Originating in the Agile methodology of Extreme Programming, Test Driven Development (TDD) has become accepted as a mainstream best practice, and is being adopted by major organisations as means of improving code quality and developer productivity.

Because Test Driven Development involves such a major inversion of most developers' ways of thinking and working, the course is strongly exercise based - it is necessary to spend a large part of the two days of the workshop practicing test-first development. Typically developers find TDD initially strange, but go on to find it quite liberating, and become "test infected" (unable to write code without having first devised unit tests.)

The exercises are based on the Java programming language, and use the tools most central to TDD in Java, including Eclipse, JUnit and some of its extensions, Easymock, and Emma.

Prerequisites

Competence in Java, or similar object-oriented programming language