I don't like using them everywhere, but they're very handy for inline anonymous functions.
But it really pains me when I see
export const foo = () => {}
instead of
export function foo() {}
But it really pains me when I see
export const foo = () => {}
instead of
export function foo() {}
But everywhere else they reduce readability of the code with no tangible benefit I am aware of.
myArray.sort(function(a,b){return a-b})
`function(a,b){return a-b;}` is different from `(a,b) => a - b`
And `function diff(a,b) {return a-b;}` is different from `const diff(a,b) => a - b;`.
One that could enforce these styles. Because not only is the export const foo = () {}
painful on itself, it will quite certainly get intermixed with the
function foo() {}
and then in the next library a
const foo = function() {}
and so on. I'd rather have a consistently irritating style, than this willy-nilly yolo style that the JS community seems to embrace.
[1] https://eslint.org/docs/latest/rules/func-style
[2] https://eslint.org/docs/latest/rules/prefer-arrow-callback
It's not opinionated, but requiring you to form your own opinion or at least choose from a palette of opinions.
It requires effort to opt-in rather than effort to opt-out.
The community doesn't frown on code that's not adhering to the common standard or code that doesn't pass the "out of the box" linter.
So, if I have a typescript project with a tree of some 20 dependencies (which is, unfortunately, a tiny project), I'll have at least five styles of code when it browse through it. Some JS, some TS, some strictly linted with "no-bikeshedding", some linted with configs that are bigger than the codebase itself. Some linted with outdated. Many not linted at all. It's really a mess. Even if each of the 20 dependencies themselves are clean, beauties, the whole is an inconsistent mess.
> Some JS, some TS
I think the JS community has done remarkably well amongst dynamically typed languages in settling on one form of gradual typing and adopting it fervently (Flow no longer has any market share at all). Whereas the last time I checked Python still had the Mypy/Pywright divide, and Ruby had the Sorbet/RBS dichotomy.
Ultimately though, most of your critique boils down to the fact that JS (unlike Rust and Go) isn't maintained by a single monolithic entity, and therefore there's no one to dictate the standards you're looking for. If Deno were the sole caretaker of JS for example, we'd have a standard linter and formatter devoid of complex configuration, but Deno doesn't control JS.
This is a consequence of JS being a collaborative product of the various browser vendors, TC39, and the server side JS runtimes that have adapted JS to run on servers. The advantage of this of course though is that JS can run natively in the browser. I think that's a decent tradeoff to make in exchange for having to wade through dependencies with different ideas about when it's appropriate to use arrow functions.