Why I Prefer &#function&# Declarations for Top-Level Symbols (But Won&#t Use Them Anymore)

Today, we’ve decided to use arrow functions exclusively at work.

We have a common ESLint config, and the team voted to unify this rule across all projects.

And honestly I'm not a fan of this particular rule

Personally... function declarations feels more expressive, at least for top-level symbols:

some-screen-of-my-app.tsx

import {} ...

export function SomeScreen(props: Props) {
  const { myContext } = useMyContext()
  const [state, setState] = useState()

  const doSomething = () => { ... }
  const handleSomething = () => { ... }

  return <>...</>
 }

function SomeInternalComponent() { ... }

This is how i'm used to write components: declaring a function feels like a chapter title in a novel.

function Chapter3(storySoFar: Props) {
   // where the Hero meets the Villain
}

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But I do understand the team need: depending on the original author of a module we might find at first level const () => {} or function.

The main argument is that "arrow functions are more readable" (which i disagree with)

import {} ...

const SomeInternalComponent = () => { ... }

export const SomeScreen = (props: Props) => {
  const { myContext } = useMyContext()
  const [state, setState] = useState()

  const doSomething = () => { ... }
  const handleSomething = () => { ... }

  return <>...</>
 }

I tried to find some technical advantage to support my preference... some nerd *pitimini* [ something small or insignificant ] that moves the balance on my benefit but since we all agree on the following:

• No Classes (just functions)
• No global stuff (modern modules)
• No this

There are no significant differences between each one.

Diving into Details:

const foo = () => { ... }

• No hoisting
• function's name is derived from the variable's name ("foo")
• Can't be overwritten later like foo=...
• Doesn't create the prototype object foo.prototype
• Can't be used as a constructor new foo()
• Doesn't have arguments
• this value is defined by where the function is declared

function foo() { ... }

• Hoisting
• function name is obv.
• Can be overwritten like foo = ...
• Creates the object prototype foo.prototype
• new is allowed like: new foo() (which would link the prototype)
• this value is defined by how the function is called

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In the end, I prefer the Superior Clarity of function for top-level components, but the will of the many prevails.
Kidding, I will adapt. Having a unified style will help to maintain a cohesive codebase.

???.

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thanks for reading

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