yunlongzha_try_nodejs/textsubmit/node_modules/npm/lib/logout.js

try it

module.exports = logout

var dezalgo = require('dezalgo')
var log = require('npmlog')

var npm = require('./npm.js')
var mapToRegistry = require('./utils/map-to-registry.js')

logout.usage = 'npm logout [--registry=<url>] [--scope=<@scope>]'

function logout (args, cb) {
  cb = dezalgo(cb)

  mapToRegistry('/', npm.config, function (err, uri, auth, normalized) {
    if (err) return cb(err)

    if (auth.token) {
      log.verbose('logout', 'clearing session token for', normalized)
      npm.registry.logout(normalized, { auth: auth }, function (err) {
        if (err) return cb(err)

        npm.config.clearCredentialsByURI(normalized)
        npm.config.save('user', cb)
      })
    } else if (auth.username || auth.password) {
      log.verbose('logout', 'clearing user credentials for', normalized)
      npm.config.clearCredentialsByURI(normalized)
      npm.config.save('user', cb)
    } else {
      cb(new Error(
        'Not logged in to', normalized + ',', "so can't log out."
      ))
    }
  })
}