Code Smell 15 — Missed Preconditions

Assertions, Preconditions, Postconditions and invariants are our allies to avoid invalid objects. Avoiding them leads to errors.

Photo by Jonathan Chng on Unsplash

Problems

Solutions

Examples

Sample Code

Wrong

Right

Detection

Tags

Conclusion

Always be explicit on object integrity.

Turn on production assertions.

Even if it brings performance penalties.

Data and object corruption is harder to find.

Fail fast is a blessing.

More info

Relations

Writing a class without its contract would be similar to producing an engineering component (electrical circuit, VLSI (Very Large Scale Integration) chip, bridge, engine…) without a spec. No professional engineer would even consider the idea.

Bertrand Meyer

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Dev Genius

Coding, Tutorials, News, UX, UI and much more related to development

Maximiliano Contieri

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I’m senior software engineer specialized in declarative designs. S.O.L.I.D. and agile methodologies fan.

Dev Genius

Coding, Tutorials, News, UX, UI and much more related to development

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