Infinite code smells! We see several symptoms and situations that make us doubt the quality of our development. Let's look at some possible solutions. Most of these smells are just hints of something that might be wrong. They are not rigid rules. Previous Code Smells Part I Part II Part III Part IV Part V Part VI Part VII Part VIII Part IX Part X Part XI Part XII Part XIII Part XIV Let's continue... Code Smell 71 - Magic Floats Disguised as Decimals TL;DR Don't trust numbers on immature languages like JavaScript. Problems Violation Principle of Least Surprise Accidental Complexity Wrong decimal representations. Solutions Choose Mature Languages. Represent . Decimals with Decimals Sample Code Wrong console.log(0.2 + 0.1) 
// 0.30000000000000004

//We are adding two decimal numbers
// 2/10  +  1/10 
// Result should be 3/10 as we learnt at school Right class Decimal {
  constructor(numerator) {
    this.numerator = numerator;    
  }
   plus(anotherDecimal) {
      return new Decimal(this.numerator + anotherDecimal.numerator);
  }
   toString() {
      return "0." + this.numerator;
   }}     
  
console.log((new Decimal(2).plus(new Decimal(1))).toString());
// 0.3

//We can represent the numbers with a Decimal class (storing only the numerator)
//or with a generic Fraction class (storing both the numerator and denominator) Detection Since this is a language feature, it is difficult to detect. We can ask our linters to prevent us from manipulating numbers this way. Tags JavaScript Premature Optimization Conclusion My first programming language was 's basic back in 1985. Commodore 64 I was very surprised to discover that 1+1+1 was not always 3. Then they introduced integer types. JavaScript is 30 years younger, and it has the same immaturity problems. More info Here is the technical (and accidental) explanation: https://blog.pankajtanwar.in/do-you-know-01-02-03-in-javascript-here-is-why Please, don't argue telling this is fine and expected since this is the binary representation. These numbers are decimals, we should represent them as decimals. If you think representing them as floats is a great performance improvement, you are wrong. Premature optimization is the root of all evil. Floating Point Standard - 83 pages The purpose of computing is insight, not numbers - Richard Hamming Code Smell 72 - Return Codes APIs, Return codes, C Programming Language, We've all been there. TL;DR: Don't return codes to yourself. Raise Exceptions. Problems IFs Code Polluting Outdated documentation Coupling to accidental codes. Functional logic polluted. Solutions Change Ids and return Generic Exceptions. Distinguish Happy Path from Exception Path. Sample Code Wrong function createSomething(arguments) {
    //Magic Creation
    success = false; //we failed

    //We failed to create
    if (!success) {
        return {
            object: null,
            errorCode: 403,
            errorDescription: 'We didnt have permddtttttttttission to create...'
        };
    }

    return {
        object: createdObject,
        errorCode: 400,
        errorDescription: ''
    };
}

var myObject = createSomething('argument');
if (myObject.errorCode != 400) {
    console.log(myObject.errorCode + ' ' + myObject.errorDescription)
}
//but myObject does not hold My Object but an implementative
//and accidental array 
//from now on me need to remember this Right function createSomething(arguments) {
    //Magic Creation
    success = false; //we failed

    //We failed to create
    if (!success) {
        throw new Error('We didnt have permission to create...');
    }

    return createdObject;
}

try {
    var myObject = createSomething('argument');
    //no IFS, just happy path
} catch (exception) {
    //deal with it!
    console.log(exception.message);
}
// myObject holds my expected object Detection We can teach our linters to find patterns of integer and strings returns coupled with ifs and return checking. Tags Exceptions Conclusion Ids and codes are external identifiers. They are useful when you need to interact with an external system (for example an API Rest). We should not use them on our own systems and our own internal APIs. Create and raise generic exceptions. Only create specific exceptions if you are ready to handle them, and they have specialized behavior. Don't create Exceptions. anemic Avoid favoring return codes. immature and premature optimized languages More info https://hackernoon.com/how-to-get-rid-of-annoying-ifs-forever-zuh3zlo http://nicolecarpenter.github.io/2016/03/15/clean-code-chapter-7-error-handling.html Error handling is important, but if it obscures logic, it’s wrong - Robert Martin Code Smell 73 - Exceptions for Expected Cases Exceptions are handy Gotos and flags. Let's abuse them. TL;DR: Do not use exceptions for flow control. Problems Readability Principle of least astonishment Violation. Solutions Use Exceptions just for unexpected situations. Exceptions handle . Read the contract. contract violations Sample Code Wrong try {
	for (int i = 0;; i++)
		array[i]++;
	} catch (ArrayIndexOutOfBoundsException e) {}

//Endless loop without end condition Right for (int index = 0; index < array.length; index++)
		array[index]++;

//index < array.length breaks execution Detection This is a semantic smell. Unless we use machine learning linters it will be very difficult to find the mistakes. Tags Readability Conclusion Exceptions are handy, and we should definitively use them instead of returning codes. The boundary between correct usage and wrong usage is blur like so many design principles. Relations Code Smell 72 - Return Codes More info Don't use exceptions for flow control Java Zone Stack Exchange Stack Overflow When debugging, novices insert corrective code; experts remove defective code - Richard Pattis Code Smell 74 - Empty Lines Breaking the code to favor readability asks for refactor. TL;DR Don't add empty lines to your methods. Extract them! Problems Readability Kiss Low Reuse Solutions Extract Method Refactor Remove unneeded lines. Sample Code Wrong <?

function translateFile() {
    $this->buildFilename();
    $this->readFile();
    $this->assertFileContentsAreOk();
    //A lot of lines more
    
    //Empty space to pause definition    
    $this->translateHiperLinks();
    $this->translateMetadata();
    $this->translatePlainText();
    
    //Yet Another empty space
    $this->generateStats();
    $this->saveFileContents();
    //A lot of more lines
} Right <?

function translateFile() {
    $this->readFileToMemoy();
    $this->translateContents();
    $this->saveFileContents();  
} Detection This is a policy smell. Every linter can detect blank lines and warn us. Tags Readability Long Methods Conclusion Empty lines are harmless, but show us an opportunity to break the code into small steps. If you break your code with comments, it is also a code smell asking for a refactor. It’s OK to figure out murder mysteries, but you shouldn’t need to figure out code.  You should be able to read it - Steve McConnell Code Smell 75 - Comments Inside a Method Comments are often a code smell. Inserting them inside a method calls for an urgent refactor. TL;DR Don't add comments inside your methods. Extract them and leave declarative comments just for not obvious design decisions. Problems Readability Kiss Low Reuse Bad Documentation Solutions Extract Method Refactor Remove not declarative comments. Sample Code Wrong function recoverFromGrief() {
    // Denial stage
    absorbTheBadNews();
    setNumbAsProtectiveState();
    startToRiseEmotions();
    feelSorrow();

    // Anger stage
    maskRealEffects();
    directAngerToOtherPeople();
    blameOthers();
    getIrrational();

    // bargaining stage
    feelVulnerable();
    regret();
    askWhyToMyself();
    dreamOfAlternativeWhatIfScenarios();
    postoponeSadness();

    // depression stage
    stayQuiet();
    getOverwhelmed();
    beConfused();

    // acceptance stage
    acceptWhatHappened();
    lookToTheFuture();
    reconstructAndWalktrough();
} Right function recoverFromGrief() {
    denialStage();
    angerStage();
    bargainingStage();
    depressionStage();
    acceptanceStage();
}

function denialStage() {
    absorbTheBadNews();
    setNumbAsProtectiveState();
    startToRiseEmotions();
    feelSorrow();
}

function angerStage() {
    maskRealEffects();
    directAngerToOtherPeople();
    blameOthers();
    getIrrational();
}

function bargainingStage() {
    feelVulnerable();
    regret();
    askWhyToMyself();
    dreamOfAlternativeWhatIfScenarios();
    postoponeSadness();
}

function depressionStage() {
    stayQuiet();
    getOverwhelmed();
    beConfused();
}

function acceptanceStage() {
    acceptWhatHappened();
    lookToTheFuture();
    reconstructAndWalktrough();
} Detection This is a policy smell. Every linter can detect comments not in the first line and warn us. Tags Readability Long Methods Comments Conclusion Comments are a code smell. If you need to document a design decision, you should do it before the actual method code. Relations Code Smell 03 - Functions Are Too Long Code Smell 74 - Empty Lines Code Smell 05 - Comment Abusers Don't get suckered in by the comments, they can be terribly misleading: Debug only the code - Dave Storer And that’s all for now… The next article will explain 5 more code smells!

Flow

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

Bite-Sized Blockchain Guides Part 1: What is a Blockchain?

Buy My Book

How to Find The Stinky Parts of Your Code [Part XV]

About Author

Comments

TOPICS

THIS ARTICLE WAS FEATURED IN

Related Stories

Untitled Story

10 Predictions About the Future of Finance

106 Stories To Learn About Clean Code

100 Pieces of Programming Advice from the Book Clean Code by Robert Martin

110 Stories To Learn About Refactoring

3 Things Coding And Prose Writing Have In Common According To Cory House

10 Predictions About the Future of Finance

106 Stories To Learn About Clean Code

100 Pieces of Programming Advice from the Book Clean Code by Robert Martin

110 Stories To Learn About Refactoring

3 Things Coding And Prose Writing Have In Common According To Cory House

Light-Mode

Classic

Newspaper

Dark-Mode

Neon Noir

Minty

HN StartUps