node-version-call-local

Call a function in a Node version found in PATH.

This is a lightweight alternative to node-version-call that finds an existing Node in PATH rather than installing one. Use this when you need to execute code in a different Node version without the overhead of installation dependencies.

Installation

npm install node-version-call-local

Usage

Immediate call

import call from 'node-version-call-local';

// Call a worker in any Node > 0.12 found in PATH
const result = call('>0.12', '/path/to/worker.js', { callbacks: true }, arg1, arg2);

Bound caller (for repeated calls)

import { bind } from 'node-version-call-local';

// Create a bound caller
const worker = bind('>0.12', '/path/to/worker.js', { callbacks: true });

// Call it multiple times
worker(arg1, callback);
worker(arg2, callback);

API

`call(version, workerPath, options?, ...args)`

Execute a file in a Node version found in PATH.

version - Semver constraint ('>0.12', '>=18', '^16') or exact ('v18.0.0')
workerPath - Path to the file to execute
options - Execution options (see below)
args - Arguments to pass to the worker

Returns the result from the worker.

`bind(version, workerPath, options?)`

Create a bound caller for repeated use.

version - Semver constraint or exact version
workerPath - Path to the file to execute
options - Execution options (see below)

Returns a function (...args) => result that calls the worker.

Options

interface CallOptions {
  callbacks?: boolean;      // Enable callback serialization (default: true)
  spawnOptions?: boolean;   // Use spawnOptions for npm env setup (default: false)
  env?: NodeJS.ProcessEnv;  // Environment variables (default: process.env)
}

callbacks - When true, the worker can use callbacks that get serialized across the process boundary
spawnOptions - When true, sets up proper npm environment (PATH, npm_* vars) for running npm commands
env - Custom environment variables to pass to the worker

Comparison with node-version-call

Feature	node-version-call-local	node-version-call
Version not found	Throws error	Installs it
Dependencies	Lightweight	Heavy (install chain)
Version binding	At bind time	At call time
Use case	Polyfills, bootstrap code	Testing, exact versions

Example: HTTPS polyfill for old Node

import { call } from 'node-version-call-local';

const major = +process.versions.node.split('.')[0];
const noHTTPS = major === 0;

function fetchFile(url, callback) {
  if (noHTTPS) {
    // Current Node can't do HTTPS, find one that can
    try {
      const result = call('>0', __filename, { callbacks: true }, url);
      callback(null, result);
    } catch (err) {
      callback(err);
    }
    return;
  }

  // Modern Node - fetch directly
  https.get(url, callback);
}

Example: npm install polyfill

import { bind } from 'node-version-call-local';

const major = +process.versions.node.split('.')[0];

// Worker that runs npm install
const workerPath = path.join(__dirname, 'workers', 'npmInstall.js');

// Need spawnOptions for npm environment
const npmInstall = bind('>10', workerPath, { callbacks: true, spawnOptions: true });

function install(packageName, callback) {
  if (major > 10) {
    // Current Node is fine
    runNpmInstall(packageName, callback);
    return;
  }

  // Use older Node found in PATH
  npmInstall(packageName, callback);
}

License

MIT