node-environment-flags

Polyfill/shim for process.allowedNodeEnvironmentFlags

node-environment-flags is a rough polyfill and shim for process.allowedNodeEnvironmentFlags, which was introduced in Node.js v10.10.0.

Install

Requires Node.js v6.0.0 or newer.

$ npm i node-environment-flags

If the current Node.js version is v10.10.0 or newer, the native implementation will be provided instead.

const nodeEnvironmentFlags = require('node-environment-flags');

nodeEnvironmentFlags.has('--require'); // true

require('node-environment-flags/shim')();

process.allowedNodeEnvironmentFlags.has('--require'); // true

This module approximates what process.allowedNodeEnvironmentFlags provides in versions of Node.js prior to v10.10.0. Since process.allowedNodeEnvironmentFlags is based on NODE_OPTIONS (introduced in v8.0.0), the set of supported flags for versions older than v8.0.0 is highly theoretical.
Version ranges are matched using semver.
This module is granular to the minor Node.js version number; patch version numbers are not considered.
Results for unmaintained (odd) versions of Node.js are based on data for the most recent LTS version; e.g., running this module against Node.js v7.10.0 will yield the same results as would v6.14.0.
Prior art: @ljharb's util.promisify