• 4.1 Introduction to testability and mock objects

  • 4.1.1 What’s this unit about?

• 4.2 Lesson 1: Test levels

  • 4.2.1 Test levels: Unit and System testing
  • 4.2.2 Integration testing
  • 4.2.3 The testing pyramid

• 4.3 Lesson 2: Mock Objects

  • 4.3.1 Hard-to-test dependencies
  • 4.3.2 Hands-on Inspecting the Invoice classes
  • 4.3.3 Mock objects
  • 4.3.4 Using Mockito, a mocking framework
  • 4.3.5 Hands-on: Getting Mockito to run
  • 4.3.6 Controllability and Observability

• 4.4 Lesson 3: Design for testability

  • 4.4.1 What’s design for testability
  • 4.4.2 Principles of Testable Architectures
  • 4.4.3 Dependency Injection
  • 4.4.4 Dependency injection vs Dependency Inversion Principle

• 4.5 Lesson 4: The pragmatic side

  • 4.5.1 To Mock or not to Mock
  • 4.5.2 Interview: Steve Freeman on the importance of testability
  • 4.5.3 Interview: Tim van der Lippe on unit vs integration tests

• 4.6 Takeaways

  • 4.6.1 Summary
  • 4.6.2 Additional Readings