TL;DR: Don't return multiple values.

Problems

• Coupling

• Missing Abstraction

• Readability

• Extensibility

Solutions

1. Create a return object grouping the tuple

2. Reify it into an object with cohesion and behavior (not a DTO or Dictionary)

3. Look for the object in the real world using the MAPPER

4. try to return void and delegate the solution to the modified object avoiding accidental mutations

Context

A function returning multiple values in languages that allow it is a problem.

Developers can use this hack to avoid reifying concepts.

Some languages are: Javascript, Go, Lua, Matlab, PHP, Python, Rust, and Swift

Sample Code

Wrong

func getNameAndAge() -> (String, Int) {
    let name = "John"
    let age = 30
    return (name, age)
}

Right

struct PeopleProfile {
    let name: String
    let age: Int
}

// We reify the PeopleProfile object
func getNameAndAge() -> PeopleProfile {
    let name = "John"
    let age = 30
    let profile = PeopleProfile(name: name, age: age)
    return profile
}

Detection

[X] Automatic

This is a language smell.

We can tell our linters to warn us.

Tags

• Coupling

Conclusion

This is yet another language feature that hinders clean code and blinds us from seeing missing abstractions in the Bijection.

Relations

More Info

Disclaimer

Code Smells are my opinion.

Credits

Photo by Edgar Soto on Unsplash

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By relieving the brain of all unnecessary work, a good notation sets it free to concentrate on more advanced problems, and in effect increases the mental power of the race. Before the introduction of the Arabic notation, multiplication was difficult, and division even of integers called into play the highest mathematical faculties. Our modern power of easy reckoning with decimal fractions is the almost miraculous result of the gradual discovery of a perfect notation.

Alfred North Whitehead

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This article is part of the CodeSmell Series.