Code Smell 114 — Empty Class

Have you encountered classes without behavior? Classes are their behavior.

Photo by Kelly Sikkema on Unsplash

TL;DR: Remove all empty classes.

Problems

• Bijection Fault
• Namespace Polluting
• Classes used as DTOs
• Classes used as global references

Solutions

1. Remove the classes and replace them with objects instead.

2. If your classes are Anemic Exceptions, remove them.

Context

Many developers still think classes are data repositories.

They couple different behavior concept with returning different data.

Sample Code

Wrong

Right

Detection

[X] Automatic

Several linters warn us of empty classes.

We can also make our own scripts using metaprogramming.

Tags

• Behavior

Conclusion

Classes are what they do, their behavior.

Empty classes do nothing.

Relations

Code Smell 26 — Exceptions Polluting

Code Smell 40 — DTOs

Code Smell 60 — Global Classes

Code Smell 01 — Anemic Models

More Info

The one and only software design principle

Refactoring 004 — Remove Unhandled Exceptions

An error arises from treating object variables (instance variables) as if they were data attributes and then creating your hierarchy based on shared attributes. Always create hierarchies based on shared behaviors, side.

David West

Software Engineering Great Quotes

This article is part of the CodeSmell Series.

How to Find the Stinky parts of your Code