Code Smell 156 — Implicit Else

We learn if/else on our first programming day. Then we forget the else

We learn if/else on our first programming day. Then we forget the else

TL;DR: Be explicit. Even with Else.

Problems

• Readability

• Cognitive Load

• Unforeseen conditions

• Fail Fast Principle violation

Solutions

1. Write the explicit else

Context

If we early return on an IF sentence we can omit the else part.

Afterward, we Remove the IF and use polymorphism.

That is when we miss the real cases.

Sample Code

Wrong

function carBrandImplicit(model) {
  if (model === 'A4') {
    return 'audi';
  }
  return 'Mercedes-Benz';
}

Right

function carBrandExplicit(model) {
  if (model === 'A4') {
    return 'audi';
  }
  if (model === 'AMG') {
    return 'Mercedes-Benz';
  }

  // Fail Fast
  throw new Exception('Model not found);
}

Detection

[X] Automatic

We can check syntax trees and parse them and warn for missing else.

We can also rewrite them and perform mutation testing.

Tags

• Conditionals

Conclusion

This kind of smell brings a lot of public debate, and hate.

We must exchange opinions and value each pros and cons.

Relations

Code Smell 102 — Arrow Code
Nested IFs and Elses are very hard to read and testblog.devgenius.io

Code Smell 36 — Switch/case/elseif/else/if statements
First programming lesson: Control structures. Senior developer lesson: avoid them.blog.devgenius.io

More Info

Stop Using Implicit Else

When To Use Implicit Else

Fail Fast
Failure is fashionable. Making is much easier than thinking and failures are not stigma, let’s take this idea to our…codeburst.io

How to Get Rid of Annoying IFs Forever
Why the first instruction we learn to program should be the last to use.blog.devgenius.io

Credits

Photo by Elena Mozhvilo on Unsplash

The biggest issue on software teams is making sure everyone understands what everyone else is doing.

Martin Fowler

Software Engineering Great Quotes
Sometimes a short thought can bring amazing ideas.blog.devgenius.io

This article is part of the CodeSmell Series.

How to Find the Stinky parts of your Code
The code smells bad. Let’s see how to change the aromas.blog.devgenius.io