martin-fowler-refactoring

name	martin-fowler-refactoring
description	Apply Martin Fowler's catalog to identify code smells and select systematic refactorings.
disable-model-invocation	true

Martin Fowler Refactoring Guide

Workflow

1. Analyze - Examine the code for code smells from the table below
2. List - Document code sections exhibiting specific smells
3. Propose - Suggest concrete refactorings with before/after examples
4. Implement - Execute the refactorings after human approval

Code Smells to Refactorings

Code Smell	Primary Refactorings
Mysterious Name	Rename Function, Rename Variable, Rename Field, Change Function Declaration
Duplicated Code	Extract Function, Slide Statements, Pull Up Method
Long Function	Extract Function, Replace Temp with Query, Decompose Conditional, Replace Conditional with Polymorphism, Replace Loop with Pipeline
Long Parameter List	Replace Parameter with Query, Preserve Whole Object, Introduce Parameter Object, Remove Flag Argument, Combine Functions into Class
Global Data	Encapsulate Variable
Mutable Data	Encapsulate Variable, Split Variable, Slide Statements, Separate Query from Modifier, Remove Setting Method, Replace Derived Variable with Query
Divergent Change	Split Phase, Move Function, Extract Class
Shotgun Surgery	Move Function, Move Field, Combine Functions into Class, Combine Functions into Transform, Inline Function
Feature Envy	Move Function, Extract Function
Data Clumps	Introduce Parameter Object, Preserve Whole Object, Extract Class
Primitive Obsession	Replace Primitive with Object, Replace Type Code with Subclasses, Replace Conditional with Polymorphism, Extract Class, Introduce Parameter Object
Repeated Switches	Replace Conditional with Polymorphism
Loops	Replace Loop with Pipeline
Lazy Element	Inline Function, Inline Class, Collapse Hierarchy
Speculative Generality	Collapse Hierarchy, Inline Function, Inline Class, Change Function Declaration, Remove Dead Code
Temporary Field	Extract Class, Move Function, Introduce Special Case
Message Chains	Hide Delegate, Extract Function, Move Function
Middle Man	Remove Middle Man, Inline Function, Replace Superclass with Delegate, Replace Subclass with Delegate
Insider Trading	Move Function, Move Field, Hide Delegate, Replace Subclass with Delegate, Replace Superclass with Delegate
Large Class	Extract Class, Extract Superclass, Replace Type Code with Subclasses, Replace Conditional with Polymorphism
Alternative Classes with Different Interfaces	Change Function Declaration, Move Function, Extract Superclass
Data Class	Encapsulate Record, Remove Setting Method, Move Function, Extract Function, Split Phase
Refused Bequest	Push Down Method, Push Down Field, Replace Subclass with Delegate, Replace Superclass with Delegate
Comments	Extract Function, Change Function Declaration, Introduce Assertion

Refactoring Categories

• Composing Functions: Extract Function, Inline Function, Extract Variable, Inline Variable, Change Function Declaration, Encapsulate Variable, Rename Variable, Introduce Parameter Object, Combine Functions into Class, Combine Functions into Transform, Split Phase, Preserve Whole Object

• Encapsulation: Encapsulate Record, Encapsulate Collection, Replace Primitive with Object, Replace Temp with Query, Extract Class, Inline Class, Hide Delegate, Remove Middle Man, Replace Subclass with Delegate, Replace Superclass with Delegate

• Moving Features: Move Function, Move Field, Move Statements into Function, Move Statements to Callers, Replace Inline Code with Function Call, Slide Statements, Split Loop, Replace Loop with Pipeline, Remove Dead Code

• Organizing Data: Split Variable, Rename Field, Replace Derived Variable with Query, Change Reference to Value, Change Value to Reference

• Simplifying Conditionals: Decompose Conditional, Consolidate Conditional Expression, Consolidate Duplicate Conditional Fragments, Remove Control Flag, Replace Nested Conditional with Guard Clauses, Replace Conditional with Polymorphism, Introduce Special Case, Introduce Assertion

• Refactoring APIs: Separate Query from Modifier, Parameterize Function, Remove Flag Argument, Replace Parameter with Query, Replace Query with Parameter, Remove Setting Method, Replace Constructor with Factory Function, Replace Function with Command, Replace Command with Function

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