It smells because there are likely many instances where it could be edited or improved. Most of these smells are just hints of something that might be wrong. Therefore, they are not required to be fixed per se… (You should look into it, though.) Previous Code Smells You can find all the previous code smells (Part i - XXXV) . here Let's continue... Code Smell 176 - Changes in Essence Mutation is good. Things change. TL;DR: Don't change essential attributes or behavior Problems violation Bijection Mutability Ripple Effect Solutions Protect essential attributes from change. Remove setters Refactorings Refactoring 001 - Remove Setters Context Heraclitus said: “No man ever steps in the same river twice. For it’s not the same river and he’s not the same man.” The man stays the same in essence. But his body evolves. Sample Code Wrong const date = new Date();

date.setMonth(4); Right const date = new Date("2022-03-25"); Detection Manual [x] This is a semantic smell. We need to model which attributes/behaviors are and which are accidental. essential Tags Mutability Conclusion We need to favor immutable objects. Objects can mutate in ways; not in essential ones. accidental Relations Code Smell 16 - Ripple Effect More Info The Evil Power of Mutants Disclaimer Code Smells are just my . opinion Credits Photo by on Nick Fewings Unsplash Changes in software design will eventually mean "one step forward, two steps back". It is inevitable. Salman Arshad Code Smell 177 - Missing Small Objects We see small primitive data everywhere TL;DR: Don't forget to model the smallest ones Problems Primitive obsession Solutions Find responsibilities for small objects in the . MAPPER Reify them. Context Since the early computing days, we map all we see to the familiar primitive data types: Strings, Integers, Collections, etc. Mapping to dates violates abstraction and principles. fail-fast in the , we describe a Wordle word to be different than a or , since they don't have the same responsibilities. Wordle TDD Kata String Char(5) Sample Code Wrong public class Person {

    private final String name; 

    public Person(String name) {
        this.name = name;
    }
} Right public class Name {

    private final String name; 


    public Name(String name) {
        this.name = name;
        // Name has its own creation rules, comparison etc.
        // Might be different than a string
    }

}

  

public class Person {

    private final Name name; 

    public Person(Name name) {
        // name is created as a valid one,
        // we don't need to add validations here 

        this.name = name;
    }
} Detection Manual [x] This is a semantic smell. It is related to design activity Exceptions In a very small number of mission-critical systems, we have a tradeoff from abstraction to performance. This is not the usual case. We do premature optimization by not relying on a modern computer and virtual machine optimizations. As always, we need to stick to evidence in real-world scenarios. Tags Primitive Conclusion Finding small objects is a very hard task requiring experience to make a good job and avoid overdesign. There's in choosing how and when to map something. no silver bullet Relations Code Smell 122 - Primitive Obsession More Info Fail Fast How to Create a Wordle with TDD in Javascript Disclaimer Code Smells are just my . opinion Credits Photo by on Shane Aldendorff Unsplash The secret to building large apps is never build large apps. Break your applications into small pieces. Then, assemble those testable, bite-sized pieces into your big application. Justin Meyer Code Smell 178 - Subsets Violation Invisible objects have rules we need to enforce at a single point. TL;DR: Create Small objects and restrict your domain. Problems Fault Bijection Fail fast principle violation validation Repeated Code Solutions Create small objects and validate the domain. Context This is a primitive obsession smell. are a subset of . EmailAddresses string are a subset of . Valid Ages Real are a subset of . Ports Integers A is a subset of String. wordle word Sample Code Wrong destination = "destination@example.com"
  

destination = "destination.example.com"

// No error thrown Right public class EmailAddress {

    public String emailAddress;


    public EmailAddress(String address) {

        string expressions = @"^\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$";

        if (!Regex.IsMatch(email, expressions) {

          throw new Exception('Invalid address');

        }

        this.emailAddress = address;

    }

}



destination = new EmailAddress("destination@example.com"); Not to be confused with the anemic Java version Detection Manual [x] This is a semantic smell. Tags Primitive Obsession Conclusion We need to be loyal to the bijection of the real world. Subsets are very important for early validations and fail fast principle. Relations Code Smell 122 - Primitive Obsession More Info Fail Fast Disclaimer Code Smells are just my . opinion Credits Photo by on Mona Eendra Unsplash Every craftsman starts his or her journey with a basic set of good-quality tools. Andrew Hunt Code Smell 179 - Known Bugs Every software has a list of known bugs. Why? TL;DR: Don't track bugs. Fix them. Problems Hard to-track lists Technical Debt Functional Debt Solutions Stop calling it a Bug Reproduce the . Defect Cover the scenario with automation. Make the most straightforward fix (even hardcoding solutions) Refactor Welcome to TDD! Context We don't like to be interrupted. Then, we create lists and delay fixes and solutions. We should be able to change software easily. We need to improve our software if we can't do quick fixes and corrections. Not by creating To-Fix lists. Sample Code Wrong <?

function divide($numerator, $denominator) {
  return $numerator / $denominator;  
  // FIXME denominator value might be 0
  // TODO Rename function
} Right <?

function integerDivide($numerator, $denominator) {
  if (denominator == 0) {
    throw new DivideByZero();
  }
  return $numerator / $denominator;  
}

// we pay our debts Detection Automatic [x] We need to avoid creating bugs and issues. Tags Technical Debt Conclusion We need to discourage bugs and issue trackers on the engineering side. Of course, customers need to track their findings, and we need to address them ASAP. Relations Code Smell 148 - ToDos More Info Famous Bugs Stop Calling them 'Bugs' Disclaimer Code Smells are just my . opinion Credits Photo by on Justin Lauria Unsplash In general, the longer you wait before fixing a bug, the costlier (in time and money) it is to fix. Joel Spolsky Code Smell 180 - BitWise Optimizations Bitwise operators are faster. Avoid these micro-optimizations. TL;DR: Don't use bitwise operators unless your business model is bitwise logic. Problems Readability Cleverness Premature Optimization Maintainability Violation Bijection Solutions Improve readability Context Some clever programmers solve problems we don't have. We should optimize code based on evidence and use the scientific method. We should benchmark only if necessary and improve code only if really necessary and bear the cost of changeability and maintainability. Sample Code Wrong const nowInSeconds = ~~(Date.now() / 1000) Right const nowInSeconds = Math.floor(Date.now() / 1000) Detection Semi-Automatic [x] We can tell our linters to warn us and manually check if it is worth the change. Exceptions Real-time and mission-critical software. Tags Premature Optimization Conclusion If we find this code in a pull request or code review, we need to understand the reasons. If they are not justified, we should do a rollback and change it to a normal logic. Relations Code Smell 20 - Premature Optimization Code Smell 165 - Empty Exception Blocks Code Smell 06 - Too Clever Programmer Code Smell 129 - Structural Optimizations More Info Tilde Operator ~~ Javascript BitWise Operators Disclaimer Code Smells are just my . opinion Credits Photo by on Frédéric Barriol Unsplash Original Article . Here Watch the little things; a small leak will sink a great ship. Benjamin Franklin 5 more code smells are coming soon…

How to Find the Stinky Parts of Your Code [Part XXXVII]

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