Infinite code, smells! 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. They are not required fixed per se… ( You should look into it though.) 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 Part XV Part XVI Let's continue... Code Smell 81 - Result result = ??? TL;DR: Use good names always. Result is always a very bad name. Problems Readability Solutions Rename . result If you don't know how to name it, just name the variable with the same name as the last function call. Don't use IDEs without automatic refactors. Sample Code Wrong var result;

result = lastBlockchainBlock();
//

// Many function calls

addBlockAfter(result); Right var lastBlockchainBlock;

lastBlockchainBlock = findlastBlockchainBlock();
//...

// Many function calls 
// we should refactor them to minimize space
// between variable definition and usage

addBlockAfter(lastBlockchainBlock); Detection We must forbid the word result to be a variable name. Tags Readability Conclusion is an example of generic and meaningless names. Result Refactoring is cheap and safe. Always leave the campground cleaner than you found it. When you find a mess on the ground, clean it, doesn’t matter who did it. Your job is to always leave the ground cleaner for the next campers. Relations Code Smell 79 - TheResult More info . What is in a name? Part I: Rehab Credits Photo by on KMA . Unsplash Code is like humor. When you have to explain it, it’s bad. Cory House Code Smell 82 - Tests Violating Encapsulation Objects work fine and fulfill business objectives. But we need to test them. Let's break them. TL;DR: Don't write methods with the only purpose of being used in your tests. Problems Encapsulation Violation. Bad interfaces Coupling Solutions Don't break encapsulation. Test must be in full control. If you cannot control your object, you are coupled. Decouple them! Sample Code Wrong <?

class Hangman {
    private $wordToGuess;

    function __construct() {
        $this->wordToGuess = getRandomWord();
        //Test is not in control of this
    }

    public function getWordToGuess(): string {
        return $this->wordToGuess;
        //Sadly we need to reveal this
    }
}

class HangmanTest extends TestCase {
    function test01WordIsGuessed() {
        $hangmanGame = new Hangman();
        $this->assertEquals('tests', $hangmanGame->wordToGuess());
        //how can we make sure the word is guessed?
    }
} Right <?

class Hangman {
    private $wordToGuess;

    function __construct(WordRandomizer $wordRandomizer) {
        $this->wordToGuess = $wordRandomizer->newRandomWord();
    }
}

class MockRandomizer implements WordRandomizer {
    function newRandomWord(): string {
        return 'tests';
    }
}

class HangmanTest extends TestCase {
    function test01WordIsGuessed() {
        $hangmanGame = new Hangman(new MockRandomizer());
        //We are in full control!
        $this->assertFalse($hangmanGame->wordWasGuessed());
        $hangmanGame->play('t');
        $this->assertFalse($hangmanGame->wordWasGuessed());
        $hangmanGame->play('e');
        $this->assertFalse($hangmanGame->wordWasGuessed());
        $hangmanGame->play('s');
        $this->assertTrue($hangmanGame->wordWasGuessed());
        //We just test behavior
    }
} Detection This is a design smell. We can detect we need a method just for test. Tags Information Hiding Conclusion White-box tests are fragile. They test implementation instead of behavior. Relations Code Smell 52 - Fragile Tests Code Smell 28 - Setters More Info Should I Test Private Methods Credits This smell was inspired by @ Rodrigo Twitter Nothing makes a system more flexible than a suite of tests. Robert Martin Code Smell 83 - Variables Reassignment Variable reuse is something we see in big chunks of code. TL;DR: Don't reuse variable names. You break readability and refactor chances and gain nothing but laziness. Problems Readability Refactor chances Missed Optimization Mutability Garbage Collection Missed Opportunities Solutions Define, use and dispose variables. Keep your Definition, Usage and Destroy variables short. Sample Code Wrong class Item:
  def __init__(self, name):
    self.name = name
  def taxesCharged(self):
    return 1;
class Money:
  pass 

lastPurchase = Item('Soda');
# Do something with the purchase

taxAmount = lastPurchase.taxesCharged();
# Lots of stuff related to the purchase
# I drink the soda

# I cannot extract method from below without passing
# useless lastPurchase as parameter

# a few hours later..
lastPurchase = Item('Whisky');
# I bough another drink

taxAmount += lastPurchase.taxesCharged(); Right class Item:
  def __init__(self, name):
    self.name = name
  def taxesCharged(self):
    return 1;
class Money:
  pass 
  
def buySupper():
  supperPurchase = Item('Soda');
  # Do something with the purchase
 
  # Lots of stuff related to the purchase
  # I drink the soda
  return supperPurchase;

def buyDrinks():
  # I could extract method! 

  # a few hours later..
  drinksPurchase = Item('Whisky');
  # I bough another drink
  
  return drinksPurchase;

taxAmount = buySupper().taxesCharged() + buyDrinks().taxesCharged(); Detection Many linters can warn us from reusing variables Tags Readability Conclusion Reusing variables is a non-contextual copy and paste hint. Relations Code Smell 03 - Functions Are Too Long More Info The Evil power of Mutants Stack Exchange Wikiversity Credits Photo by on Robby McCullough Unsplash Twitter Either way you look at it (DRY or laziness), the idea is the same: make your program flexible. When change comes (and it always does), you'll have a much easier time changing with it. Chris Pine Code Smell 84 - Max < Min (Javascript) Some functions do not behave as expected. Sadly, most programmers accept them. TL;DR: Don't trust max() and min() functions. Just ignore them. Problems Principle of least astonishment Violation. Bijection Unexpected Results Solutions Use mature languages. Avoid and functions. max() min() Model Infinites carefully. Sample Code Wrong console.log(Math.max() > Math.min());

//returns false

console.log(Math.max());

//returns -Infinite Right console.log(Math.max() > Math.min());
console.log(Math.max());

//returns Exception. Not enough arguments passed.
//Max requires at least one argument Detection These functions belong to the standard Math library. Therefore, they are not easy to avoid. We can block them on our linters. Tags Javascript Conclusion We need to be very careful using functions that violate real-world concepts using language tricks. Relations Code Smell 69 - Big Bang (JavaScript Ridiculous Castings) More Info Principle of least astonishment Bijection Principle MAPPER Credits Photo by on Cris Baron Unsplash Inspired by @@ Oliver Jumpertz Twitter Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning. Rick Cook Code Smell 85 - And Functions Do not perform more than requested. TL;DR: Unless you need atomicity, do not perform more than one task. Problems Coupling Single Responsibility Principle violation Readability Low Cohesion Testability Solutions Break the function Sample Code Wrong def fetch_and_display_personnel():
  data = # ...
  
  for person in data:
    print(person) Right def fetch_personnel():
  return # ...

def display_personnel(data):
  for person in data:
    print(person) Detection Functions including "and" are candidates. However, we need to check them carefully since there might be false positives. Tags Readability Naming Conclusion We should avoid doing more than needed, and our functions should be both minimal and atomic. More Info What exactly is a name — Part II Rehab Credits Photo by on Paul Unsplash This smell was inspired by Twitter If it takes more than a sentence to explain what you are doing, it’s almost always a sign that what you are doing is too complicated. Sam Altman And that’s all for now… The next article will explain 5 more code smells!

Twitter

Winner of Noonies 2020 for the award Hacker Noon Contributor of the Year - REFACTORING.

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

About Author

Comments

TOPICS

THIS ARTICLE WAS FEATURED IN

Related Stories

From Helpful to Harmful: How AI Recommendations Destroyed My OS

Building Scalable SaaS: My Real-World Journey Using spatie/laravel-multitenancy for Multi-Tenant Arc

The "Comment" Fallacy: Why Self-Documenting Code is Still the Goal

Flip the Script: Write the Tests, Let AI Write the Implementation

Building a Filesystem From Scratch: Inside the Reactor That Powers BarkFS

Everyone's Using the Wrong Algebra in AI

From Helpful to Harmful: How AI Recommendations Destroyed My OS

Building Scalable SaaS: My Real-World Journey Using spatie/laravel-multitenancy for Multi-Tenant Arc

The "Comment" Fallacy: Why Self-Documenting Code is Still the Goal

Flip the Script: Write the Tests, Let AI Write the Implementation

Building a Filesystem From Scratch: Inside the Reactor That Powers BarkFS

Everyone's Using the Wrong Algebra in AI

Light-Mode

Classic

Newspaper

Minty

Dark-Mode

Neon Noir

Minty

HN StartUps