Refactoring Pattern 1: Move Method

Learning Goals

• Explain Move Method and how it promotes abstraction and single responsibility principle
• Identify scenarios for which Move Method is the appropriate refactoring pattern to use
• Implement Move Method

Supplies

• You should have a copy of this extraction of Chapter 7.

First 12 minutes individually:

• Briefly read Move Method section from 167 to 172
• Carefully re-read the code sections on 170, 171, and 172
• Reflect on these key ideas of Move Method:
  • Move Method is useful when you have two objects (e.g. Class A & Class B) that are too tightly coupled
    • One indication you should use it is when you have several methods in Class A that have the name of Class B
    • You move the method from Class A to Class B and update any references
  • Remember to consider the context of Class B when choosing a name for the moved method
• Try refactoring this example scenario (you should already have this cloned) using Move Method. As you move methods around, make sure the linked test still passes
• If you finish early, apply this refactoring pattern to the Enigma examples found under Additional Resources in the main lesson for today
• If you still have more time, apply this refactoring pattern to your current project

Final 3 minutes in your small group:

• Answer the following questions:
  • Why would you move a method from one class to another?
  • How can you identify methods that should be moved?
  • How can you implement red, green, refactor to successfully move the method?
  • Should you rename the moved method? If so, how?
• Compare solutions