Test Driven Development and Refactoring

A 2-3 day course in which students will learn the fundamental skills of Test Driven Development and Refactoring.

Audience:

• Programmers of all levels of experience who desire to improve their coding skills._

Duration:

• The two day version is weighted towards lecture and demonstration with a minimum of exercises.
• The three day version shifts the weight towards in-class practice and exercises, withoutdiminishing the lectures and demonstrations.

Outcomes
After this class students will:

• ...understand how, when, and when not to refactor code.
• ...be able to refactor functions and classes into cleaner, more understandable forms.
• ...know, and be able to execute the three laws of Test Driven Development.
• ...be able to create test suites that enable refactoring.
• ...understand the basics of mocking and test-doubling in order to test theinterplay between components.
• ...be able to properly organize robust test suites.
• ...understand, and be able to employ, the strategy for testing and refactoring legacy code.

Outline

• Why TDD
  • The Three Laws.
  • The Benefits
    • Reduced Debugging.
    • Tests and Documents
    • Design Improvement
    • Refactoring.
  • TDD is Double Entry Bookkeeping.

• Simple Demonstration of the three laws.
  • Exercize.

• Test Design
  • Decoupling Tests and Production Code.
  • Fragile Tests
  • The Specific/Generic Dichotomy.
  • The Transformation Priority Premise.

• Mocks and Test Doubles
  • Dummies
  • Stubs
  • Spies
  • Mocks
  • Fakes

• Architecture and Tests
  • Statism vs Mockism
  • The TDD Uncertainty Principle
  • Testing across architectural boundaries.

• **Refactor
  • Code Smells
  • Remedial Refactorings
  • The process of refactoring.
  • How much is enough?

• Refactoring Demonstration
  A long demonstration that integrates TDD and Refactoring.
  • Refactoring the Test.
  • Refactoring the Code.
  • The role of design.
  • Comparison of Test vs Prodution design.

• Exercises.
  Several coding exercises and demonstrations as time permits.