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

More Info

• How to Get Rid of Annoying Ifs Forever

Credits

Photo by Morgan Housel on Unsplash

Thanks to Nico K. for this suggestion.

---

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

---

This article is part of the CodeSmell Series.