Node-retrieve-globals NPM

node-retrieve-globals

Execute a string of JavaScript using Node.js and return the global variable values and functions.

Supported on Node.js 16 and newer.
Uses var, let, const, function, Array and Object destructuring assignment.
Async-only as of v5.0.
Can return any valid JS data type (including functions).
Can provide an external data object as context to the local execution scope
Transforms ESM import statements to work with current CommonJS limitations in Node’s vm.
Uses Node’s vm module to execute JavaScript ⚠️ The node:vm module is not a security mechanism. Do not use it to run untrusted code. codeGeneration (e.g. eval) is disabled by default; use setCreateContextOptions({codeGeneration: { strings: true, wasm: true } }) to re-enable. Works with or without --experimental-vm-modules flag (for vm.Module support). (v5.0.0 and newer) Future-friendly feature tests for when vm.Module is stable and --experimental-vm-modules is no longer necessary. (v5.0.0 and newer)
In use on: JavaScript in Eleventy Front Matter (and Demo) WebC’s <script webc:setup>

Installation

Available on npm

npm install node-retrieve-globals

Usage

Works from Node.js with ESM and CommonJS:

import { RetrieveGlobals } from "node-retrieve-globals";
// const { RetrieveGlobals } = await import("node-retrieve-globals");

And then:

let code = `var a = 1;
const b = "hello";

function hello() {}`;

let vm = new RetrieveGlobals(code);

await vm.getGlobalContext();

Returns:

{ a: 1, b: "hello", hello: function hello() {} }

Pass in your own Data and reference it in the JavaScript code

let code = `let ref = myData;`;

let vm = new RetrieveGlobals(code);

await vm.getGlobalContext({ myData: "hello" });

Returns:

{ ref: "hello" }

Advanced options

// Defaults shown
let options = {
	reuseGlobal: false, // re-use Node.js `global`, important if you want `console.log` to log to your console as expected.
	dynamicImport: false, // allows `import()`
	addRequire: false, // allows `require()`
	experimentalModuleApi: false, // uses Module#_compile instead of `vm` (you probably don’t want this and it is bypassed by default when vm.Module is supported)
};

await vm.getGlobalContext({}, options);

Changelog

v6.0.0 Changes import and require to be project relative (not relative to this package on the file system).
v5.0.0 Removes sync API, swap to async-only. Better compatibility with --experimental-vm-modules Node flag.
v4.0.0 Swap to use Module._compile as a workaround for #2 (Node regression with experimental modules API in Node v20.10+)
v3.0.0 ESM-only package. Node 16+