20 stories with 5 code smells each are 100 code smells, right? 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 Part XVII Part XVIII Part XIX Let's continue... Code Smell 96 - My Objects You don't own objects. TL;DR: don't use as a name prefix. my Problems Lack of context Bijection Fault Solutions Remove prefix. my Change to a role suggesting name. Context Several old tutorials use the word 'my' as a lazy name.
This is vague and lead to context mistakes. Sample Code Wrong MainWindow myWindow = Application.Current.MainWindow as MainWindow; Right MainWindow salesWindow = Application.Current.MainWindow as MainWindow;

/*

Since window is instanciated, we are currently working
with a specialized window playing a special role

*/ Detection Automatic [x] We can tell our linters and static checkers to search for this prefix and warn us. Tags Naming Conclusion Avoid using . Objects change according to the usage context. my More Info What exactly is a name — Part II Rehab Credits Photo by on Michał Bożek Unsplash Thinking about my experience of modifying code, I see that I spend much more time reading the existing code than I do writing new code. If I want to make my code cheap, therefore, I should make it easy to read. Kent Beck Software Engineering Great Quotes Code Smell 97 - Error Messages Without Empathy We should take special care with error descriptions for the users (and ourselves). TL;DR: Use meaningful descriptions and suggest corrective actions. Problems The Least Surprise Principle Solutions Use declarative error messages Show clear exit actions Context Programmers are seldom UX experts. We also underestimate the fact we can be on both sides of the counter. Sample Code Wrong alert("Cancel the appointment?", "Yes", "No");

// No consequences
// Options not clear Right alert("Cancel the appointment? \n" +
      "You will lose all the history", 
      "Cancel Appointment", 
      "Keep Editing");

// Consequences are clear
// Choice options have context Detection Manual [x] We need to read all exception messages in code reviews. Tags Exceptions UX Conclusion We need to think in our end users when raising exception or showing messages. Credits Photo by on visuals Unsplash While it is a known fact that programmers never make mistakes, it is still a good idea to humor the users by checking for errors at critical points in your program. Robert D. Schneider Code Smell 98 - Speling Mistakes Spelling and readability are very important for humans and not important for machines. TL;DR: Take care of your names. Problems Readability Harder to search terms in code. Solutions Spellcheck your code. Use an IDE with spellchecking Context Many of us don't speak English as our first language. We need to have extra care for our texts and names. 😀 This article has a typo in its title as proof of context and also a clickbait Sample Code Wrong comboFeededBySupplyer = supplyer.providers(); Right comboFedBySupplier = supplier.providers(); Detection Tags Readability Naming Code Styling Conclusion Pay close attention to your names. You will probably be the person reading the code in a few months. Relations Code Smell 48 - Code Without Standards More Info What exactly is a name — Part I The Quest What exactly is a name — Part II Rehab Credits Photo by on Brett Jordan Unsplash Inside every well-written large program is a well-written small program. C.A.R. Hoare Code Smell 99 - First Second How many times do we see lazy argument names? TL;DR: Name your arguments according to the role and not the accidental position Problems Readability Intention Revealing Names Solutions Use meaningful names Context When writing methods, we usually don't stop to find decent names. We never refactor the obvious, neither. Sample Code Wrong class Calculator:
  def subtract(self, first, second):
    return first - second

class CalculatorTest  
  def test_multiply():
    assert equals(first, second) Right class Calculator:
  def subtract(self, minuend, subtrahend):
    return minuend - subtrahend

class CalculatorTest  
  def test_multiply():
    assert equals(expectedValue, realValue) Detection Manual [x] We can warn for forbidden words like 'first' and 'second' as argument names. Tags Readability Conclusion Always follow rule suggesting parameter. Name your collaborators according to the role. Relations Code Smell 65 - Variables Named after Types More Info What exactly is a name — Part II Rehab Credits Photo by on Priscilla Du Preez Unsplash Final source code is the real software design. Jack Reeves Code Smell 100 - GoTo GOTO was considered harmful 50 years ago TL;DR: Don't ever use GoTo. Problems Readability Hard to follow code Solutions Replace with structured code GOTO Use exceptions Context I started programming in Basic. GOTO was heavily abused there. I had to learn structured programming from scratch in Rehab mode. Sample Code Wrong for x < 0 {
    if x > -1e-09 {
      goto small
    }
    z = z / x
    x = x + 1
  }
  for x < 2 {
    if x < 1e-09 {
      goto small
    }
    z = z / x
    x = x + 1
  }

  if x == 2 {
    return z
  }

  x = x - 2
  p = (((((x*_gamP[0]+_gamP[1])*x+_gamP[2])*x+_gamP[3])*x+_gamP[4])*x+_gamP[5])*x + _gamP[6]
  q = ((((((x*_gamQ[0]+_gamQ[1])*x+_gamQ[2])*x+_gamQ[3])*x+_gamQ[4])*x+_gamQ[5])*x+_gamQ[6])*x + _gamQ[7]
  return z * p / q

small:
  if x == 0 {
    return Inf(1)
  }
  return z / ((1 + Euler*x) * x)
} Right for x < 0 {
    if x > -1e-09 {
      return small(x, z)
    }
    z = z / x
    x = x + 1
  }
  for x < 2 {
    if x < 1e-09 {
      return small(x, z)
    }
    z = z / x
    x = x + 1
  }

  if x == 2 {
    return z
  }

  x = x - 2
  p = (((((x*_gamP[0]+_gamP[1])*x+_gamP[2])*x+_gamP[3])*x+_gamP[4])*x+_gamP[5])*x + _gamP[6]
  q = ((((((x*_gamQ[0]+_gamQ[1])*x+_gamQ[2])*x+_gamQ[3])*x+_gamQ[4])*x+_gamQ[5])*x+_gamQ[6])*x + _gamQ[7]
  return z * p / q

small(x, z) {
  if x == 0 {
     return Inf(1)
   }
   return z / ((1 + Euler*x) * x)
 }
} Detection Automatic [x] In languages supporting , our linters can warn us against its usage. GOTO Tags Readability Conclusion We acknowledged GOTO problems a few decades ago. The problem is still present in like GoLang, PHP, Perl etc. modern languages Most programmers luckily avoid GOTO sentence. Next goal will be to consider harmful . null usage Courtesy XKCD Relations Code Smell 12 - Null More Info Goto Statement considered harmful Wikipedia Credits Photo by on Jens Johnsson Unsplash It is practically impossible to teach good programming to students that have had a prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration. Edsger Dijkstra Software Engineering Great Quotes And that’s all for now, We have hit 100 milestone. The next article will explain 5 more code smells!

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How to Find the Stinky Parts of Your Code [Part XX]: We have Reached 100!

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Maximiliano Contieri

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How to Find the Stinky Parts of Your Code [Part XX]: We have Reached 100!

Too Long; Didn't Read

Maximiliano Contieri

About Author

TOPICS

THIS ARTICLE WAS FEATURED IN...

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