Refactoring 030 - How to Avoid Accidental Redundancy

Written by mcsee | Published 2025/07/13
Tech Story Tags: clean-code | refactoring | code-smells | software-development | object-oriented-programming | object-oriented | how-to-avoid-redundancy | hackernoon-top-story

TLDR1. Identify methods that receive owned attributes 2. Remove those parameters from the method signature 3. Replace usage with direct access to the attribute 4. Rename the method if needed to match the new intentionvia the TL;DR App

Avoid accidental redundancy

TL;DR: Don’t pass attributes your object already owns

Problems Addressed πŸ˜”

Related Code Smells πŸ’¨

https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxxviii

https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxxv

https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-ii-o96s3wl4

https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-x-i7r34uj

https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxix

Steps πŸ‘£

  1. Identify methods that receive owned attributes
  2. Remove those parameters from the method signature
  3. Replace usage with direct access to the attribute
  4. Rename the method if needed to match the new intention

Sample Code πŸ’»

Before 🚨

class Auto {
  constructor(motor) {
    this.motor = motor
  }

  startEngine(motor) {
    motor.ignite()
  }
}

// Usage
const motor = new Motor()
const auto = new Auto(motor)

auto.startEngine(motor)
// Redundant and maybe inconsistent

After πŸ‘‰

class Auto {
  constructor(motor) {
    this.motor = motor
  }
    
  // 1. Identify methods that receive owned attributes    
  startEngine() {
    // 2. Remove those parameters from the method signature  
    // 4. Rename the method if needed to match the new intention
    this.motor.ignite()
  }
}

// Adjust usage to call without passing motor
const motor = new Motor()
const auto = new Auto(motor)

// 3. Replace usage with direct access to the attribute  
auto.startEngine() // No parameter needed

Type πŸ“

  • [x]Automatic

Safety πŸ›‘οΈ

This refactoring is straightforward and safe if you have good test coverage.

Why is the Code Better? ✨

You remove accidental complexity.

You stop pretending your method needs information from the outside.

You reduce the cognitive load and improve encapsulation.

You clarify which attributes are essential.

You avoid passing the same data through different paths.

You reduce parameter redundancy and simplify method signatures.

You eliminate the possibility of passing inconsistent values since methods now directly access the object's state.

This makes the code more maintainable and reduces the cognitive load when reading method calls.

The methods become more cohesive by relying on their own object's data rather than external parameters.

How Does it Improve the Bijection? πŸ—ΊοΈ

This refactoring enhances the Bijection by aligning object behavior more closely with real-world entities.

You match the real-world concept: an object uses what it owns.

You improve the anthropomorphism and avoid unrealistic indirection.

You also reduce internal and external coupling.

Limitations ⚠️

This works only if the method always uses the internal attribute.

If you need to inject different versions for testing or variations, consider using dependency injection or a strategy pattern.

Refactor with AI πŸ€–

Suggested Prompt: 1. Identify methods that receive owned attributes 2. Remove those parameters from the method signature 3. Replace usage with direct access to the attribute 4. Rename the method if needed to match the new intention

Without Proper Instructions

With Specific Instructions

ChatGPT

ChatGPT

Claude

Claude

Perplexity

Perplexity

Copilot

Copilot

You

You

Gemini

Gemini

DeepSeek

DeepSeek

Meta AI

Meta AI

Grok

Grok

Qwen

Qwen

Tags 🏷️

  • Encapsulation

Level πŸ”‹

  • [x]Beginner

Related Refactorings πŸ”„

https://maximilianocontieri.com/refactoring-010-extract-method-object?embedable=true

https://hackernoon.com/refactoring-016-building-with-the-essence?embedable=true

https://maximilianocontieri.com/refactoring-020-transform-static-functions?embedable=true

https://hackernoon.com/refactoring-024-replace-global-variables-with-dependency-injection?embedable=true

  • Remove Parameter
  • Introduce Parameter Object

Credits πŸ™

Image by F. Muhammad on Pixabay


This article is part of the Refactoring Series.

https://maximilianocontieri.com/how-to-improve-your-code-with-easy-refactorings?embedable=true


Written by mcsee | I’m a sr software engineer specialized in Clean Code, Design and TDD Book "Clean Code Cookbook" 500+ articles written
Published by HackerNoon on 2025/07/13