readme.md

Code Smell 91 - Test Asserts without Description

We are big fans of xUnit. But we don't care much for the programmers.

TL;DR: Use asserts with declarative descriptions.

Problems

• Readability

• Hard debugging

• Time waste

Solutions

1. Put a nice descriptive assertion

2. Share guides for problem-solving

Sample Code

Wrong

<?

public function testNoNewStarsAppeared(): void
  {
     $expectedStars = $this->historicStarsOnFrame();
     $observedStars = $this->starsFromObservation();
     // These sentences get a very large collection
  
     $this->assertEquals($expectedStars, $observedStars);
     // If something fails you will have a very hard time debugging
    }

Right

<?

public function testNoNewStarsAppeared(): void
  {
     $expectedStars = $this->historicStarsOnFrame();
     $observedStars = $this->starsFromObservation();
     // These sentences get a very large collection
  
     $newStars = array_diff($expectedStars, $observedStars);
  
     $this->assertEquals($expectedStars, $observedStars,
         'There are new stars ' . print_r($newStars,true));
     // Now you can see EXACTLY why the assertion failed with a clear and
     // declarative Message
    }

Detection

Since assert and assertDescription are different functions, we can adjust our policies to favor the latter.

Tags

• Test Smells

Conclusion

Be respectful to the reader of your assertions.

It might even be yourself!

More Info

• XUnit: Assert Description Deprecation

Credits

Photo by Startaê Team on Unsplash

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Always code as if the guy who ends up maintaining your code will be a violent psychopath who knows where you live.

John Woods

Software Engineering Great Quotes

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This article is part of the CodeSmell Series.

How to Find the Stinky Parts of your Code