An object that appears and disappears mysteriously

TL;DR: Add the necessary indirection layers, but no more.

Problems

• Accidental complexity

• Readability

• YAGNI violation

Solutions

1. Remove the intermediate object

Context

A poltergeist (or gypsy wagon) is a short-lived object used to perform initialization or to invoke methods in another, more permanent class.

An object is responsible for many small tasks, resulting in excessive coupling and a lack of cohesion in the code.

Sample Code

Wrong

public class Driver
{
    private Car car;

    public Driver(Car car)
    {
        this.car = car;
    }

    public void DriveCar()
    {
        car.driveCar();
    }
}

Car porsche = new Car();
Driver homer = new Driver(porsche);
homer.DriveCar();

Right

Car porsche = new Car();

porsche.driveCar();
// We don't need the driver

Detection

[X] Manual

This is a design smell.

Tags

• Complexity

Conclusion

Don't add accidental complexity to the essential complexity we already have.

Remove middleman objects if they are not needed.

Relations

More Info

• Wikipedia

Disclaimer

Code Smells are my opinion.

Credits

Photo by Lan Gao on Unsplash

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The art of programming is the art of organizing complexity, of mastering multitude and avoiding its bastard chaos as effectively as possible.

E. W. Dijkstra

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This article is part of the CodeSmell Series.