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1const { Minipass } = require('minipass')2const fetch = require('minipass-fetch')3const { promiseRetry } = require('@gar/promise-retry')4const ssri = require('ssri')5const { log } = require('proc-log')6const { redact: cleanUrl } = require('@npmcli/redact')7 8const CachingMinipassPipeline = require('./pipeline.js')9const { getAgent } = require('@npmcli/agent')10const pkg = require('../package.json')11 12const USER_AGENT = `${pkg.name}/${pkg.version} (+https://npm.im/${pkg.name})`13 14const RETRY_ERRORS = [15  'ECONNRESET', // remote socket closed on us16  'ECONNREFUSED', // remote host refused to open connection17  'EADDRINUSE', // failed to bind to a local port (proxy?)18  'ETIMEDOUT', // someone in the transaction is WAY TOO SLOW19  // from @npmcli/agent20  'ECONNECTIONTIMEOUT',21  'EIDLETIMEOUT',22  'ERESPONSETIMEOUT',23  'ETRANSFERTIMEOUT',24  // Known codes we do NOT retry on:25  // ENOTFOUND (getaddrinfo failure. Either bad hostname, or offline)26  // EINVALIDPROXY // invalid protocol from @npmcli/agent27  // EINVALIDRESPONSE // invalid status code from @npmcli/agent28]29 30const RETRY_TYPES = [31  'request-timeout',32]33 34// make a request directly to the remote source,35// retrying certain classes of errors as well as36// following redirects (through the cache if necessary)37// and verifying response integrity38const remoteFetch = (request, options) => {39  // options.signal is intended for the fetch itself, not the agent.  Attaching it to the agent will re-use that signal across multiple requests, which prevents any connections beyond the first one.40  const agent = getAgent(request.url, { ...options, signal: undefined })41  if (!request.headers.has('connection')) {42    request.headers.set('connection', agent ? 'keep-alive' : 'close')43  }44 45  if (!request.headers.has('user-agent')) {46    request.headers.set('user-agent', USER_AGENT)47  }48 49  // keep our own options since we're overriding the agent50  // and the redirect mode51  const _opts = {52    ...options,53    agent,54    redirect: 'manual',55  }56 57  return promiseRetry(async (retryHandler, attemptNum) => {58    const req = new fetch.Request(request, _opts)59    const url = cleanUrl(req.url)60    try {61      let res = await fetch(req, _opts)62      if (_opts.integrity && res.status === 200) {63        // we got a 200 response and the user has specified an expected64        // integrity value, so wrap the response in an ssri stream to verify it65        const integrityStream = ssri.integrityStream({66          algorithms: _opts.algorithms,67          integrity: _opts.integrity,68          size: _opts.size,69        })70        const pipeline = new CachingMinipassPipeline({71          events: ['integrity', 'size'],72        }, res.body, integrityStream)73        // we also propagate the integrity and size events out to the pipeline so we can use74        // this new response body as an integrityEmitter for cacache75        integrityStream.on('integrity', i => pipeline.emit('integrity', i))76        integrityStream.on('size', s => pipeline.emit('size', s))77        res = new fetch.Response(pipeline, res)78        // set an explicit flag so we know if our response body will emit integrity and size79        res.body.hasIntegrityEmitter = true80      }81 82      res.headers.set('x-fetch-attempts', attemptNum)83 84      // do not retry POST requests, or requests with a streaming body85      // do retry requests with a 408, 420, 429 or 500+ status in the response86      const isStream = Minipass.isStream(req.body)87      const isRetriable = req.method !== 'POST' &&88          !isStream &&89          ([408, 420, 429].includes(res.status) || res.status >= 500)90 91      if (isRetriable) {92        if (typeof options.onRetry === 'function') {93          options.onRetry(res)94        }95 96        /* eslint-disable-next-line max-len */97        log.http('fetch', `${req.method} ${url} attempt ${attemptNum} failed with ${res.status}`)98        return retryHandler(res)99      }100 101      return res102    } catch (err) {103      const code = (err.code === 'EPROMISERETRY')104        ? err.retried.code105        : err.code106 107      // err.retried will be the thing that was thrown from above108      // if it's a response, we just got a bad status code and we109      // can re-throw to allow the retry110      const isRetryError = err.retried instanceof fetch.Response ||111        (RETRY_ERRORS.includes(code) && RETRY_TYPES.includes(err.type))112 113      if (req.method === 'POST' || isRetryError) {114        throw err115      }116 117      if (typeof options.onRetry === 'function') {118        options.onRetry(err)119      }120 121      log.http('fetch', `${req.method} ${url} attempt ${attemptNum} failed with ${err.code}`)122      return retryHandler(err)123    }124  }, options.retry).catch((err) => {125    // don't reject for http errors, just return them126    if (err.status >= 400 && err.type !== 'system') {127      return err128    }129 130    throw err131  })132}133 134module.exports = remoteFetch135