Code Smell 118 - Return False

Checking for a boolean condition to return a boolean value is awkward

TL;DR: Don't return explicit booleans. Most boolean usages are code smells.

Problems

• Declarativeness

• Ninja Code

• Implementative solutions

Solutions

1. Return a boolean proposition instead of checking a negation.

2. Answer must be a business logic formula, not an algorithm.

Context

When dealing with boolean formulas, it is more readable to show a business boolean formula than introduce a negated IF clause.

Programmers tend to return accidental implementative solutions instead of real business rules.

Sample Code

Wrong

function canWeMoveOn() {
  if (work.hasPendingTasks())
    return false;
  else
    return true;
}

Right

function canWeMoveOn() {
  return !work.hasPendingTasks();
}

Detection

[X] Automatic

Based on syntax trees, we can safely refactor the code.

Tags

• Boolean

Conclusion

Beware of returning booleans.

After the return, you will need an If statement which is also a code smell.

Relations

Code Smell 115 - Return True

Maxi Contieri ・ Feb 20 '22

Code Smell 101 - Comparison Against Booleans

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#webdev #beginners #programming #tutorial

Code Smell 24 - Boolean Coercions

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#oop #tutorial #boolean #coercion

Code Smell 62 - Flag Variables

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#programming #oop #webdev #tutorial

Code Smell 102 - Arrow Code

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Code Smell 51 - Double Negatives

Maxi Contieri ・ Dec 24 '20

#codenewbie #tutorial #programming #oop

More Info

• How to Get Rid of Annoying Ifs Forever

Credits

Photo by Morgan Housel on Unsplash

Thanks to Nico K. for this suggestion.

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It's not at all important to get it right the first time. It's vitally important to get it right the last time.

Andrew Hunt

Software Engineering Great Quotes

Maxi Contieri ・ Dec 28 '20

#codenewbie #programming #quotes #software

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This article is part of the CodeSmell Series.

How to Find the Stinky parts of your Code

Maxi Contieri ・ May 21 '21

#codenewbie #tutorial #codequality #beginners

Comments

[GrahamTheDev]

I need to stop reading this series…my code doesn’t smell it stinks I realise as I seem to break every rule 🤣❤️

[Maxi Contieri]

Articles are guides and suggestions.
Don't take it too hard

[GrahamTheDev]

I was kidding, I am enjoying the series, it was self deprecating humour! (Or meant to be 🤣)

[Michael Otu]

I have and I am learning a lot from these series. @mcsee a question please (your opinion)

say we have the code:

function canWeMoveOn() {
  if (work.hasPendingTasks())
    return false;
  else
    return true;
}

All we want is the result of work.hasPendingTasks() and in this post, you suggested that it is better not to explicitly return a boolean.

So you refactored it to:

function canWeMoveOn() {
  return !work.hasPendingTasks();
}

Now, the refactored code looks like a wrapper around work.hasPendingTasks(); and question is that, when it happens that we have a simple single lines like, it is okay to wrap them up? I mean, we could used the work.hasPendingTasks(); directly. What do you think or encourage? Thanks

[Maxi Contieri]

canWeMoveOn the 'what'

hasPendingTaks the 'how'

they are accidentally coupled, now. But the caller to 'canWeMoveOn' does not know,
If you change your implementation or add new business rules or add a cache the caller should not be aware

I used this example here

Code Smell 123 - Mixed 'What' and 'How'

Maxi Contieri ・ Mar 22 ・ 2 min read