node/node_modules/npm/lib/commands/root.js

const { output } = require('proc-log')
const BaseCommand = require('../base-cmd.js')

class Root extends BaseCommand {
  static description = 'Display npm root'
  static name = 'root'
  static params = ['global']

  async exec () {
    output.standard(this.npm.dir)
  }
}

module.exports = Root