Code Smell 87 - Inconsistent Parameters Sorting

Be consistent with the parameters you use. Code is prose.

TL;DR: Don't confuse you readers. Keep the order.

Problems

• Readability

• Consistency

Solutions

1. Refactor and change parameters order.

2. Use named parameters

Sample Code

Wrong

function giveFirstDoseOfVaccine(person, vaccine) {
  //
}

function giveSecondDoseOfVaccine(vaccine, person) {
  //
}


giveFirstDoseOfVaccine(jane, pfizer);
giveSecondDoseOfVaccine(jane, pfizer);  //Unnoticed mistake

Right

function giveFirstDoseOfVaccine(person, vaccine) {
  //
}

function giveSecondDoseOfVaccine(person, vaccine) {
  //
}


giveFirstDoseOfVaccine(jane, pfizer);
giveSecondDoseOfVaccine(jane, pfizer);  //jane is immunized

Detection

• Some very smart linters may be able to compare arguments and hint for possible mistakes.

Tags

• Readability

Conclusion

This is a very simple smell.

Readability is very important to avoid mistakes.

Relations

Code Smell 10 - Too Many Arguments

Maxi Contieri ・ Oct 29 '20

#codenewbie #beginners #100daysofcode #oop

Credits

Photo by Lance Grandahl on Unsplash

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Computers are good at following instructions, but not at reading your mind.

Donald Knuth

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

[James Robb]

Usually for cases like this I would create a factory to avoid the ambiguity, something like:

type Vaccine = "pfizer" | "moderna"
type Patient = {
    name: string;
}
type PatientWithCoronaVaccineDetails = Patient & {
    vaccine: Vaccine;
    doses: number;
}

function vaccineFactoryForPatient(patient: PatientWithCoronaVaccineDetails) {
  // ...

  return {
    giveFirstDoseOfVaccine() {
        // ...
    },
    giveSecondDoseOfVaccine() {
        // ...
    }
  }
}
}

This way we can avoid this category of issues in the first place.