is-core-module

is-core-module

Is this specifier a node.js core module? Optionally provide a node version to check; defaults to the current node version.

Example

var isCore = require('is-core-module');
var assert = require('assert');
assert(isCore('fs'));
assert(!isCore('butts'));

TypeScript

isCore accepts any string. isCore.Module is the union of every specifier in core.json, regardless of node version, so editors can suggest them.

The types import core.json, so resolveJsonModule, esModuleInterop, and allowSyntheticDefaultImports must be enabled; some module and moduleResolution settings enable them by default, but node16 does not enable resolveJsonModule. Without them, TypeScript reports an error in this package's index.d.ts, or, with skipLibCheck, isCore.Module silently widens to string | number | symbol.

import isCore = require('is-core-module');

function isBuiltin(specifier: string): boolean {
	return isCore(specifier); // any string is accepted
}

const name: isCore.Module = 'node:fs'; // only specifiers listed in `core.json`
isCore(name, '16.0.0'); // true

Tests

Clone the repo, npm install, and run npm test

Similar packages

Other packages similar to is-core-module

builtin-modules

The builtin-modules package provides a list of the Node.js built-in modules. It is similar to is-core-module in that it helps identify core modules, but instead of checking a module name, it provides the full list of built-in modules for direct use.

resolve

The resolve package is a more complex module resolution library that can be used to resolve the path of a module like require.resolve does. It can also be used to check if a module is a core module by resolving its path and checking if it is null, which would indicate a core module. It offers more features than is-core-module but can be used for a similar purpose in some cases.