Refactoring

Aman & Chirag

ThoughtWorks Pune

If it ain’t broken, why fix it?

Good programmers write code that humans can understand

You write code once;it gets read many times

To regain control on a program that is getting out of hands

To make the next change easier

This brings us to Refactoring

Refactoring in Action

Code Smells

Duplicated Code

Long Method

Comments

Divergent Change

Shotgun Surgery

Feature Envy

Lazy Class

Switch Statements

Primitive Obsession

Method Chains

Refactoring Catalog

Refactoring Catalog

Composing methods

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Refactoring Catalog

Simplifying Conditional Expressions

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Refactoring Catalog

Making Method Calls Simpler

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Accompanying XP Practices

• TDD : “Red - Green - Refactor” mantra

• Continuous Integration

• Collective Code Ownership

• Pair Programming

Next steps for you

• Go read the book!!!

• Practice small refactorings– Explore the “Refactor” menu of your IDE

• Keep a look out for code smells in your project

To sum it up…

• Refactoring is a good technique to clean up code

• Refactoring leads to better design (especially with Test-Code-Refactor cycles)

• Most important of all: it leaves a nice feeling at the end of it all!

Thank You

• Aman King– king@thoughtworks.com

• Chirag Doshi– chirag@thoughtworks.com