Function updateCheck

deps/npm/lib/cli/update-notifier.js:18–67

(npm, spec, version, current)

// Actual check for updates. This is a separate function so that we only load this if we are doing the actual update
const updateCheck = async (npm, spec, version, current) => {
  const pacote = require('pacote')

  const mani = await pacote.manifest(`npm@${spec}`, {
    // always prefer latest, even if doing --tag=whatever on the cmd
    defaultTag: 'latest',
    ...npm.flatOptions,
    cache: false,
  }).catch(() => null)

  // if pacote failed, give up
  if (!mani) {
    return null
  }

  const latest = mani.version

  // if the current version is *greater* than latest, we're on a 'next' and should get the updates from that release train.
  // Note that this isn't another http request over the network, because the packument will be cached by pacote from previous request.
  if (gt(version, latest) && spec === '*') {
    return updateNotifier(npm, `^${version}`)
  }

  // if we already have something >= the desired spec, then we're done
  if (gte(version, latest)) {
    return null
  }

  const chalk = npm.logChalk

  // ok! notify the user about this update they should get.
  // The message is saved for printing at process exit so it will not get lost in any other messages being printed as part of the command.
  const update = parse(mani.version)
  const type = update.major !== current.major ? 'major'
    : update.minor !== current.minor ? 'minor'
    : update.patch !== current.patch ? 'patch'
    : 'prerelease'
  const typec = type === 'major' ? 'red'
    : type === 'minor' ? 'yellow'
    : 'cyan'
  const message = [
    '',
    `New ${chalk[typec](type)} version of npm available! ${chalk[typec](current)} -> ${chalk.blue(latest)}`,
    `Changelog: ${chalk.blue(`https://github.com/npm/cli/releases/tag/v${latest}`)}`,
    `To update run: ${chalk.underline(`npm install -g npm@${latest}`)}`,
    '',
  ].join('\n')

  return message
}

const updateNotifier = async (npm, spec = '*') => {
  // if we're on a prerelease train, then updates are coming fast check for a new one daily.