with with

A simple way to (almost) use the JavaScript with keyword in strict mode!

This is not a sandbox do not use it as a sandbox do not try to make it a sandbox. We will try this and fail so you don’t have to.

Installation

Node/Bun

pnpm install with-with

Deno

import withWith from "https://deno.land/x/with/mod.ts";

QuickJS

Cry.

Usage

const inaccessible = true;
withWith({ hello: "there" }, () => () => {
    // You can get types via destructuring like `() => ({ hello, ...etc }) =>`.
    console.log(hello); // Logs `there`.

    /*
     * Unlike in the real with statement, this will error because inaccessible does not exist within the scope.
     * Unfortunately it's impossible to replicate this feature.
     * To get around this, just pass all of the variables you need access to.
     */
    console.log(inaccessible);
});

Binding

withWith({ hello: "there" }, () => function () {
    console.log(this);
}, { on: "this" });

Why `() => () =>`?

To get around duplicate variable names in subscopes, some JS engines cough cough v8 simply rename them and all the references. This breaks the binding to the orginal object when you destructure to make TypeScript happy.