TL;DR: Don't focus on accidental properties. You won't need many of them.

Problems

• Anemic Models

• Properties bloating

• YAGNI violation

Solutions

• Create attributes only to support your methods (behavior).

Context

Whenever they want to model a person or an employee, junior programmers or students add an attribute 'id' or 'name' without thinking if they are really going to need them.

We need to add attributes 'on-demand' when there's enough evidence. Objects are not 'data holders'.

Sample Code

Wrong

class PersonInQueue
  attr_accessor :name, :job

  def initialize(name, job)
    @name = name
    @job = job
  end
end

Right

class PersonInQueue

  def moveForwardOnePosition
    # implement protocol
  end
end

Detection

[X] Semi-Automatic

We can detect unused attributes.

But in many cases, we need an excellent designer to validate the actual need.

Tags

• Anemic

Conclusion

Start designing your objects from the protocol.

Add attributes only when needed.

Relations

Credits

Photo by Melanie Pongratz on Unsplash

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Object thinking focuses our attention on the problem space rather than the solution space.

David West

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This article is part of the CodeSmell Series.