refactorings

name	refactorings
description	Refactoring catalog based on Martin Fowler's work. Covers composing methods (extract/inline function, extract variable), moving features (move function/field), organising data (split variable, encapsulate record/collection), simplifying conditionals (decompose/consolidate conditional, replace with polymorphism), dealing with inheritance (pull up/push down, replace superclass with delegate), and more. Use when refactoring code, choosing specific refactoring techniques, or during code review.
license	MIT
metadata	{"author":"itzcull"}

Purpose

Provide a comprehensive catalog of refactoring operations that improve code structure without changing external behaviour. Each refactoring describes a specific, mechanical transformation with clear motivation and mechanics.

When to use

• Refactoring code during the REFACTOR step of TDD
• Choosing the right refactoring technique for a code smell
• Code review discussions about structural improvements
• Learning specific refactoring mechanics
• Teaching refactoring techniques to team members

Categories

Composing methods

Extract Function, Inline Function, Extract Variable, Inline Variable, Change Function Declaration, Encapsulate Variable, Rename Variable, Introduce Parameter Object, Combine Functions into Class/Transform, Split Phase

Moving features

Move Function, Move Field, Move Statements into/out of Function, Replace Inline Code with Function Call, Slide Statements, Split Loop, Replace Loop with Pipeline

Organising data

Split Variable, Rename Field, Replace Derived Variable with Query, Change Reference to Value (and reverse), Encapsulate Record, Encapsulate Collection, Replace Primitive with Object

Simplifying conditionals

Decompose Conditional, Consolidate Conditional Expression, Replace Conditional with Polymorphism, Introduce Special Case, Introduce Assertion, Remove Flag Argument

Dealing with generalisation

Pull Up Method/Field/Constructor Body, Push Down Method/Field, Replace Type Code with Subclasses, Remove Subclass, Extract Superclass, Collapse Hierarchy, Replace Superclass with Delegate

Other

Parameterize Function, Preserve Whole Object, Remove Dead Code, Remove Middle Man, Remove Setting Method, Replace Constructor with Factory Function, Replace Function with Command, Replace Parameter with Query (and reverse), Replace Query with Parameter, Substitute Algorithm, Hide Delegate, Inline Class, Extract Class

Reference files

• Overview and full catalog
• Individual refactorings documented in references/