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 - XXXIII) . here Let's continue... Code Smell 171 - Plural Classes Classes are “my precious” TL;DR: Classes represent concepts. And concepts are singular. Problems Naming Code Standards Solutions Rename classes to singular Context Naming things is hard. We need to agree on certain rules. Sample Code Wrong class Users Right class User Detection Automatic [x] This is a syntactic rule. Tags Naming Conclusion Name concepts in the singular. Classes are concepts. More Info What exactly is a name - Part II Rehab Disclaimer Code Smells are just my . opinion Credits Photo by on Anton Malanin Unsplash We are still in the infancy of naming what is really happening on software development projects. Alistair Cockburn Software Engineering Great Quotes Code Smell 172 - Default Argument Values Not Last Function signature should be error prune TL;DR: Don't use Optional Arguments before mandatory ones. In fact: Don't use Optional Arguments at all Problems violation Fail Fast principle Readability Solutions Move your optional arguments last. Avoid . Optional Arguments Context Optional Arguments are a code smell. Defining optional arguments before mandatory ones is an error. Sample Code Wrong <?

function buildCar($color = "red", $model) {
  //...
}  
// First argument with optional argument

buildCar("Volvo");  
// Runtime error: Too few arguments to function buildCar() Right <?

function buildCar($model, $color = "Red", ){...}

buildCar("Volvo")}} 
// Works as expected def functionWithLastOptional(a, b, c='foo'):
    print(a)
    print(b)
    print(c)
functionWithLastOptional(1, 2)

def functionWithMiddleOptional(a, b='foo', c):
    print(a)
    print(b)
    print(c)
functionWithMiddleOptional(1, 2)

# SyntaxError: non-default argument follows default argument Detection Automatic [x] Many Linters can enforce this rule since we can derive it from function signature. Also, many compilers directly forbid it. Tags Readability Conclusion Try to be strict when defining functions to avoid coupling. Relations Code Smell 19 - Optional Arguments More Info Fail Fast Rule on Sonar Source Disclaimer Code Smells are just my . opinion Credits Photo by on Manuel Torres Garcia Unsplash Programs are meant to be read by humans and only incidentally for computers to execute. Donald Knuth Code Smell 173 - Broken Windows Always leave the campground cleaner than you found it.” If you find a mess on the ground, you clean it up regardless of who might have made it. TL;DR: Follow Uncle Bob's boy scout rule. Problems Readability Maintainability Solutions Leave the code better Change it Context We read code many more times than we write. We must take ownership of code with errors and leave it better. Sample Code Wrong int mult(int a,int  other) 
    { int prod
      prod= 0; 
      for(int i=0;i<other  ;i++) 
        prod+= a ; 
         return prod; 
    } 

// Formatting, naming, assignment and standards inconsistent Right int multiply(int firstMultiplier, int secondMultiplier) {
  int product = 0; 
  for(int currentIndex=0; currentIndex<secondMultiplier; currentIndex++) {
    product += firstMultiplier; 
  }
  return product; 
} 

// or just multiply them :) Detection Semi-Automatic [x] We can use other code smell detectors and leave the code in a better shape. Tags Standards Conclusion We must follow the Boy Scout rule and leave the code better. Relations Code Smell 164 - Mixed Indentations CoDe SmElL 159 - mIxEd_cASe Disclaimer Code Smells are just my . opinion Credits Photo by on Pawel Czerwinski Unsplash One broken window, left unrepaired, instills in the inhabitants of the building a sense of abandonment. People start littering. Graffiti appears. Serious structural damage begins. In a relatively short span of time, the building becomes damaged Andy Hunt Code Smell 174 - Class Name in Attributes Redundancy in names is a bad smell. Names should be contextual TL;DR: Don't prefix your attributes with your class name Problems Not Contextual Names Solutions Remove the class prefix from the attribute Context This is a naming smell, we should not read attributes in isolation and names are contextual. Sample Code Wrong public class Employee {

   String empName = "John";

   int empId = 5;

   int empAge = 32;

} Right public class Employee {

   String name;

   int id; // Ids are another smell

   int age; // Storing the age is yet another smell

} Detection Semi-Automatic [x] When the full name is included in the prefix, our linters can warn us. Tags Naming Conclusion Careful naming is a very important task. We need to name after the behavior, not type or data Relations Code Smell 188 - Redundant Parameter Names Code Smell 141 - IEngine , AVehicle, ImplCar Code Smell 96 - My Objects More Info What exactly is a name - Part II Rehab Linux Hint Disclaimer Code Smells are just my . opinion Credits Photo by on Phoenix Han Unsplash Copying skips understanding. Understanding is how you grow. You have to understand why something works or why something is how it is. When you copy it, you miss that. You just repurpose the last layer instead of understanding all the layers underneath. Jason Fried Code Smell 175 - Changes Without Coverage If your merge request has no test changed, you haven't finished your job TL;DR: Don't change the code without breaking some tests. Problems Quality Maintainability Solutions Cover your code. Context When you need to make a change, you need to update the live specification of your code. That's what tests are for. Instead of generating dead documentation of what your code does, you should write a covering use scenario. If you change uncovered tests, you need to add coverage. Suppose you change the code with existing coverage. Lucky you! Go and change your broken tests. Sample Code Wrong export function sayHello(name: string): string {

  const lengthOfName = name.length;

-  const salutation = `How are you ${name}?, I see your name has ${lengthOfName} letters!`;

+  const salutation = `Hello ${name}, I see your name has ${lengthOfName} letters!`;

  return salutation;

} Right export function sayHello(name: string): string {

  const lengthOfName = name.length;

-  const salutation = `How are you ${name}?, I see your name has ${lengthOfName} letters!`;

+  const salutation = `Hello ${name}, I see your name has ${lengthOfName} letters!`;

  return salutation;

}



import { sayHello } from './hello';



test('given a name produces the expected greeting', () => {

  expect(sayHello('Alice')).toBe(

    'Hello Alice, I see your name has 6 letters!'

  );

}); Detection Automatic [x] We can ensure all our merge requests include test code. Exceptions If your code and your tests harness live in different repositories, you might have different pull requests. Tags Quality Conclusion Test coverage is as important as functional code. The test system is our first and more loyal customer. We need to care for them. Relations Code Smell 05 - Comment Abusers Disclaimer Code Smells are just my . opinion Credits Photo by on Vincent Péré Unsplash Before you use a method in a legacy system, check to see if there are tests for it. If there aren’t, write them. When you do this consistently, you use tests as a medium of communication. Michael Feathers 5 more code smells are coming soon…

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

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