Code Smell 32 - Singletons
The most used and (in)famous design pattern in the world is causing us great harm.
29 November, 2022
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Contributors
The most used and (in)famous design pattern in the world is causing us great harm.
Problems
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Coupling
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Testability
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Accidental problems
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Multi threading
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Premature Optimization
Solutions
1.
Avoid it.
2.
Use contextual unique objects.
3.
Benchmark object creation.
Examples
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Database Access
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Globals
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Logging
Sample Code
Wrong
Right
Detection
This is a design pattern. We should avoid it by policy.
We can add linter rules for patterns like 'getInstance()' so new developers cannot infect code with this anti-pattern.
Tags
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Globals
Conclusion
This is an historical mistake already acknowledged by the community. Nevertheless, lazy developers bring it again and again. We need to reach a consensus on its drawbacks.
Relations
More Info
Credits
Photo by Maria Teneva on Unsplash
The Diagram is Not the Model. The model is not the diagram. It is an abstraction, a set of concepts and relationships between them.
Eric Evans
This article is part of the CodeSmell Series.