Lazy Class

A class that doesn’t do enough to justify existence.

Fowler & Beck

Signs of Use (Symptoms)

  • Class has only one or two trivial methods.
  • Class was created for “future use” that never came.

Why it is bad (Consequences)

  • Overhead: Extra file to navigate and maintain.
  • Indirection: Makes codebase harder to understand.

Why it happens (Root Cause)

Refactoring reduced a class’s responsibilities but didn’t remove it. Or, speculative design created empty abstractions.

When it might be okay (Exceptions)

  • Placeholder for planned expansion.

Explanation

Problem

StringHelper class with one method: capitalize().

The Flaw

Not enough behavior to deserve a class. Just inline it or use a utility.

Real world analogy

Hiring a full-time employee to just answer the phone once a week.

Refactoring Solution

  • Inline Class: Merge into another.
  • Collapse Hierarchy: If it’s a trivial subclass.

Pros and Cons (of the Antipattern)

Pros (Why people do it) Cons (The price you pay)
  • Future flexibility
    		•
  • Clutter
    		•

    Comparison

    • Related Antipatterns: Speculative Generality.
    • Related Principles: YAGNI.

    Code example

    Typescript

    Bad (The Antipattern)

    Good (The Fix)