Code Deodorant

Reference

https://refactoring.com/catalog/

https://www.jyt0532.com/toc/refactoring/

1. Long Function

Extract Function

Replace Temp with Query

Introduce Parameter Object

Preserve Whole Object

Replace Function with Command

Decompose Conditional

Replace Conditional with Polymorphism

Split Loop (重構與效能) 有時候為了讓程式碼更容易維護， 犧牲效能

2. Large Class

Extract Class

Extract Superclass

Replace Type Code with Subclasses

3. Long Parameter List

Replace Parameter with Query

Preserve Whole Object

Introduce Parameter Object

Remove Flag Argument

Combine Functions into Class

4. Data Clumps

Extract Class

Introduce Parameter Object

Preserve Whole Object

5. Primitive Obsession

Replace Primitive with Object

Replace Type Code with Subclasses

Replace Conditional with Polymorphism

Extract Class

Introduce Parameter Object

6. Repeated Switch

Replace Conditional with Polymorphism

Remove Flag Argument

7. Temporary Field

Extract Class

Move Function

Introduce Special Case

8. Alternative Classes with Different Interfaces

Change Function Declaration

Move Function

Extract Superclass

9. Refused Bequest

Push Down Method

Push Down Field

Replace Subclass with Delegate

Replace Superclass with Delegate (延伸)

10. Divergent Change

Split Phase

Move Function

Extract Function

Extract Class

11. Shotgun Surgery

Move Function

Move Field

Combine Functions into Class

Combine Function into Transform 

Split Phase

Inline Function

Inline Class

12. Parallel Inheritance Hierarchies

Move Method

Move Field

13. Duplicate Code

Extract Function

Substitute Algorithm

Pull Up Method

14. Lazy Class

Inline Function

Inline Class

Collapse Hierarchy

15. Speculative Generality

Collapse Hierarchy

Inline Function

Inline Class 

Change Function Declaration

Remove Dead Code

16. Data Class

Encapsulate Record

Remove Setting Method (this value can't change)

Move Function

Extract Function

Split Phase

17. Dead code

Remove Unreachable Code

18. Feature Envy

Move Function

Extract Function

19. Message Chains

Hide Delegate

Extract Function

Move Function

20. Middle Man

Remove Middle Man

Inline Function

Replace Superclass with Delegate

Replace Subclass with Delegate

21. Inappropriate Intimacy

Move Method

Move Field

Change Bidirectional Association to Unidirectional

Extract Class

Hide Delegate

Replace Inheritance with Delegation (https://learnku.com/docs/99-software-pattern/delegation-pattern/12018)

22. Comments

Extract Function

Change Function Declaration

Introduce Assertion

23. Global Data

Encapsulate Variable

24. Mutable Data

Encapsulate Variable

Split Variable

Slide Statements

Extract Function 

Separate Query from Modifier

Remove Setting Method (this value can't change)

Replace Derived Variable with Query

Combine Functions into Class

Combine Functions into Transform

Change Reference to Value

25. Mysterious Name

Change Function Declaration

Rename Variable

Rename Field

26. Incomplete Library Class 

Move Method

Introduce Foreign Method

Introduce Local Extension

27. Loops

Replace Loop with Pipeline

28. Insider Trading

Move Function

Move Field

Hide Delegate

Replace Subclass with Delegate

Replace Superclass with Delegate