/usr/lib/nodejs/is-npm/index.js is in node-is-npm 1.0.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | 'use strict';
module.exports = 'npm_config_username' in process.env ||
'npm_package_name' in process.env ||
'npm_config_heading' in process.env;
|