When an object changes its state the best solution is to change the attribute, isn't it?

Problems

• Mutability

• Attributes polluting

• Setters

Solutions

1 - Model states as mathematical set inclusion.

2 - State is accidental, take it away from the object.

Examples

• State diagrams

Sample Code

Wrong

Right

Detection

If we want to be extreme, we should consider every setter to be a potential state change. Linters can warn us. But we might end up getting too many false positives.

Exceptions

• Over Design

• Performance issues (if a serious benchmark supports it).

Code Smell 20 - Premature Optimization

Maxi Contieri ・ Nov 8 '20

#oop #developing #coding #codesmell

Tags

• Mutation

Conclusion

This technique is very elegant but can lead to over design. For example changing a visual component its color should be a counterexample to this smell.

We should be aware and very caution like with any other smell.

They are hints and not rigid rules.

Relations

Code Smell 28 - Setters

Maxi Contieri ・ Nov 19 '20

#oop #codenewbie #programming #webdev

More info

Mutants

Credits

Photo by Tom Crew on Unsplash

First make the change easy (warning: this might be hard), then make the easy change.

Kent Beck