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Clean code exercises - part 1

Eder Díaz on November 19, 2020

Illustration by Ivan Haidutski from Icons8 You've probably read and listen a lot about Clean Code and probably you're tired of acronyms like YAGNI...
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jonrandy profile image
Jon Randy 🎖️ •

If, in a code interview, someone wrote code along the lines of:

function someFunction() {
  if (someBooleanExpression) {
    return true
  }
  return false
}
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I wouldn't hire them

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alexmario74 profile image
Mario Santini •

I would like to know why?

I think that clean code is not the main concern on a whiteboard job interview.
But cleaning up some code can also be a good question for a candidate.

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jonrandy profile image
Jon Randy 🎖️ • • Edited

The if and two returns are entirely superfluous. This type of code to me indicates a lack of understanding of what a boolean expression is. My above example should really be written:

function someFunction() {
  return someBooleanExpression
}
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Or, better still:

const someFunction = () => someBooleanExpression
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There is nothing tricky or clever going on in my code. Being overly verbose is not the same as being clean

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alexmario74 profile image
Mario Santini •

I see.

I think that writing pseudo code on a whiteboard explaining what I have in mind, it's not the same as writing production code.

The uncecessary if and return statement will help exposing the implementation to another humans.

It's just that, I often refctor boolean expressions as you did here, so it is just that I was courious about your reasons about failing a job interview.

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jonrandy profile image
Jon Randy 🎖️ •

The code should never be written that way in the first place - it's as bad as writing something like this in pseudocode:

if true return true else return false
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Definitely a red flag

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ogzhanolguncu profile image
Oğuzhan Olguncu •

Also, violates SOLID's first principle, because now function
does two thing instead one.

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peerreynders profile image
peerreynders • • Edited

The Single Responsibility Principle has nothing to do with "do just one thing" - that is a common misconception.
The Single Responsibility Principle:

Gather together those things that change for the same reason, and separate those things that change for different reasons.

So "those (many) things that change for the same reason" revolve around the same single responsibility.

Don't Repeat Yourself is another one - it' not about removing repetition or duplication:

Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

Sometimes duplication isn't about the same thing (The Wrong Abstraction):

prefer duplication over the wrong abstraction

Also: The SOLID Design Principles Deconstructed (2013)

Basics of the Unix Philosophy:

(i) Make each program do one thing well. To do a new job, build afresh rather than complicate old programs by adding new features. (Doug McIlroy 1978)

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darkwiiplayer profile image
𒎏Wii 🏳️‍⚧️ • 
const circleStrategy = (shape) => Math.PI * shape.radius * shape.radius

const squareStrategy = (shape) => shape.width * shape.width

const rectangleStrategy = (shape) => shape.width * shape.height
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Those functions are poorly named. Proper names would be areaCircle, areaSquare and areaRectangle respectively. You can turn the names around, but putting area first makes for easier sorting.

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ederchrono profile image
Eder Díaz •

Yeah I wasn't too careful with the naming here since that wasn't the problem of the exercise. I think that calculateAreaCircle would be better though, since methods should have a present tense verb.

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darkwiiplayer profile image
𒎏Wii 🏳️‍⚧️ •

since methods should have a present tense verb

I don't see any methods in that code.

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schmelto profile image
Tom Schmelzer •

Nice and easy understanding. Thanks for sharing :)