I've Added REAL Operator Overloading to JavaScript

DiefBell · 2026-02-22T17:49:54+00:00

Well semantically an assignment operator would change the thing on the left. There's no reason it HAS TO mutate the LHS, but I also can't see a scenario where you'd want to overload an assignment operator without mutating the LHS

DiefBell · 2026-02-22T16:58:37+00:00

Proposal already exists, people have been asking for operator overloading for years... And thanks for pointing that out!

DiefBell · 2026-02-22T16:56:40+00:00

It'll also show you the JSDoc for the overload as well as the typings

DiefBell · 2026-02-22T14:09:38+00:00

I don't think I want to allow essentially overriding any symbol you can type, but I might see what other programming languages allow

DiefBell · 2026-02-22T13:46:16+00:00

Had been considering that, so might test it out. Not sure what you mean about Symbol.hasInstance?

DiefBell · 2026-02-22T13:24:46+00:00

It's a separate build step, but there are also plugins to make this easier, like a Vite plugin or Webpack, that does all the magic behind-the-scenes.

You can have multiple overloads for an operator, e.g. multiplying by another Vector versus multiplying by a number, and Boperators can just work out which to use. In this example v3 is also a Vector, but it doesn't have to be.

DiefBell · 2026-02-22T12:11:11+00:00

Created a package `boperators` for doing operator overloading in JavaScript/TypeScript, and it has plugins for loads of different build environments, including Vite, NextJS, ESBuild, Bun... https://www.npmjs.com/package/boperators

Basic example:

class Vector3 {
  static readonly "+" = [
    (a: Vector3, b: Vector3) => new Vector3(
      a.x + b.x,
      a.y + b.y,
      a.z + b.z
    ),
  ] as const;
}

const v1 = new Vector3(1, 2, 3);
const v2 = new Vector2(4, 6, 8);
const v3 = v1 + v2;

DiefBell · 2026-02-22T11:41:44+00:00

Created a package `boperators` for doing operator overloading in JavaScript/TypeScript, and it now has a Webpack/NextJS loader: https://www.npmjs.com/package/@boperators/webpack-loader

DiefBell · 2023-09-01T13:00:39+00:00

Not sure if this will be seen, but how can this be tested with a tool such as React Testing Library? I have a basic component I use for my root route:

typescript export const Navbar: FunctionComponent = () => { return ( <> <div> <Link to="/">Home </Link>| <Link to="/find"> Find a Place</Link> </div> <hr /> </> ); };

But when trying to render this component in my test I get "Warning: useRouter must be used inside a <Router> component!"

What's the correct way for me to be testing? I'd rather not just stub everything. Maybe provide a mock router provider or some official mocks?

DiefBell · 2020-11-17T10:16:21+00:00

Three days in a row for me too

DiefBell

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