Code Smell 182 - Over Generalization

We are refactoring fans. Sometimes we need to stop and think.

TL;DR: Don't make generalizations beyond real knowledge.

Problems

• Overgeneralization
• Bijection violation

Solutions

1. Think before making structural generalizations

Context

Refactoring is not just looking at structural code.

We need to refactor behavior and check if it needs an abstraction.

Sample Code

Wrong

fn validate_size(value: i32) {
    validate_integer(value);
}

fn validate_years(value: i32) {
    validate_integer(value);
}

fn validate_integer(value: i32) {
    validate_type(value, :integer);
    validate_min_integer(value, 0);
}        

Right

fn validate_size(value: i32) {
    validate_type(value, Type::Integer);
    validate_min_integer(value, 0);
}

fn validate_years(value: i32) {
    validate_type(value, Type::Integer);
    validate_min_integer(value, 0);
}

// Duplication is accidental, therefore we should not abstract it           

Detection

[X] Manual

This is a semantic smell.

Tags

• Duplication

Conclusion

Software development is a thinking activity.

We have automated tools to help and assist us. We need to be in charge.

Relations

Code Smell 46 - Repeated Code

More Info

• DRY—The Evils of Duplication

Disclaimer

Code Smells are just my opinion.

Credits

Photo by Matthew Henry on Unsplash

Duplication is far cheaper than the wrong abstraction.

Sandi Metz

Software Engineering Great Quotes

This article is part of the CodeSmell Series.

How to Find the Stinky Parts of your Code