mirror-rhinstaller-node-cache/is-core-module
2026-10-07 13:11:50 +00:00
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CHANGELOG.md 8986ea02568055672e1beddb78d7e5aed90251028babf76ed1d8d56afb5edf35 package.json 2026-10-07 13:11:50 +00:00
core.json 8986ea02568055672e1beddb78d7e5aed90251028babf76ed1d8d56afb5edf35 package.json 2026-10-07 13:11:50 +00:00
index.d.ts 8986ea02568055672e1beddb78d7e5aed90251028babf76ed1d8d56afb5edf35 package.json 2026-10-07 13:11:50 +00:00
index.js 8986ea02568055672e1beddb78d7e5aed90251028babf76ed1d8d56afb5edf35 package.json 2026-10-07 13:11:50 +00:00
LICENSE 8986ea02568055672e1beddb78d7e5aed90251028babf76ed1d8d56afb5edf35 package.json 2026-10-07 13:11:50 +00:00
package.json 8986ea02568055672e1beddb78d7e5aed90251028babf76ed1d8d56afb5edf35 package.json 2026-10-07 13:11:50 +00:00
README.md 8986ea02568055672e1beddb78d7e5aed90251028babf76ed1d8d56afb5edf35 package.json 2026-10-07 13:11:50 +00:00

is-core-module Version Badge

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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