feat(warn): http warning headers now logged

lib/registry/check-warning-header.js

@@ -0,0 +1,36 @@
+'use strict'
+
+const LRU = require('lru-cache')
+
+const WARNING_REGEXP = /^\s*(\d{3})\s+(\S+)\s+"(.*)"\s+"([^"]+)"/
+const BAD_HOSTS = new LRU({ max: 50 })
+
+module.exports = checkWarnings
+function checkWarnings (res, registry, opts) {
+  if (res.headers.has('warning') && !BAD_HOSTS.has(registry)) {
+    const warnings = {}
+    res.headers.raw()['warning'].forEach(w => {
+      const match = w.match(WARNING_REGEXP)
+      if (match) {
+        warnings[match[1]] = {
+          code: match[1],
+          host: match[2],
+          message: match[3],
+          date: new Date(match[4])
+        }
+      }
+    })
+    BAD_HOSTS.set(registry, true)
+    if (warnings['199'] && warnings['199'].message.match(/ENOTFOUND/)) {
+      opts.log.warn('registry', `Using stale data from ${registry} because the host is inaccessible -- are you offline?`)
+    } else if (warnings['199']) {
+      opts.log.warn('registry', `Unexpected warning for ${registry}: ${warnings['199'].message}`)
+    } else if (warnings['111']) {
+      // 111 Revalidation failed -- we're using stale data
+      opts.log.warn(
+        'registry',
+        `Using stale package data from ${registry} due to a request error during revalidation.`
+      )
+    }
+  }
+}

lib/registry/manifest.js

@@ -2,6 +2,7 @@
 
 const BB = require('bluebird')
 
+const checkWarnings = require('./check-warning-header')
 const fetch = require('make-fetch-happen')
 const optCheck = require('../util/opt-check')
 const pickManifest = require('./pick-manifest')
@@ -103,6 +104,7 @@ function fetchPackument (uri, registry, opts) {
     if (res.headers.get('npm-notice')) {
       opts.log.warn('notice', res.headers.get('npm-notice'))
     }
+    checkWarnings(res, registry, opts)
     const elapsedTime = Date.now() - startTime
     const attempt = res.headers.get('x-fetch-attempts')
     const attemptStr = attempt && attempt > 1 ? ` attempt #${attempt}` : ''

lib/registry/tarball.js

@@ -2,6 +2,7 @@
 
 const BB = require('bluebird')
 
+const checkWarnings = require('./check-warning-header')
 const fetch = require('make-fetch-happen')
 const manifest = require('./manifest')
 const optCheck = require('../util/opt-check')
@@ -77,6 +78,7 @@ function fromManifest (manifest, spec, opts) {
     if (res.headers.get('npm-notice')) {
       opts.log.warn('notice', res.headers.get('npm-notice'))
     }
+    checkWarnings(res, registry, opts)
     if (res.status >= 400) {
       const err = new Error(`Failed with ${res.status} while fetching ${uri}.`)
       err.code = `E${res.status}`