Code is there. Just in case. We might need it soon.

TD:LR; Don't leave code for future use.

Problems

• Complexity

• Coupling

Solutions

1. Remove dead code.

2. Leave covered and real tested code.

Sample Code

Wrong

<?

final class DatabaseQueryOptimizer {

  public function selectWithCriteria($tableName, $criteria) {
    //Make some optimizations manipulating criterias
  }

  private function sqlParserOptimization(SQLSentence $sqlSentence): SQLSentence {
    //Parse the SQL converting it to an string and then working with their nodes as strings and lots of regex
    //This was a very costly operation overcoming real SQL benefits.
    //But since we made too much work we decide to keep the code. 
  }  
}

Right

<?

final class DatabaseQueryOptimizer {

  public function selectWithCriteria($tableName, $criteria) {
    //Make some optimizations manipulating criterias
  } 
}

Detection

Using some mutation testing variants we can remove the dead code and see it test fails.

We need to have good coverage to rely on this solution.

Tags

• YAGNI

Conclusion

Dead code is always a problem.

We can use modern development techniques like TDD to ensure all code is alive.

How to Squeeze Test Driven Development on Legacy Systems

Maxi Contieri ・ Nov 26 '20

#oop #tutorial #tdd #legacy

Also Known as

• Speculative Generality

Relations

Code Smell 09 - Dead Code

Maxi Contieri ・ Oct 28 '20

#codenewbie #tutorial

More info

• Exception not Found

• Wikipedia

• Refactoring.guru

Also Known as

• Speculative Generality

Credits

Photo by Kris Mikael Krister on Unsplash

Thanks to @Apoorv Tyagi for pointing this out.

It is very hard to predict, especially the future.

Niels Bohr

Software Engineering Great Quotes

Maxi Contieri ・ Dec 28 '20

#codenewbie #programming #quotes #software

This article is part of the CodeSmell Series.

How to Find the Stinky parts of your Code

Maxi Contieri ・ May 21 '21

#codenewbie #tutorial #codequality #beginners

Last update: 2021/06/13