Handle unhandledRejections, help with cache eacces

bin/npm-cli.js

@@ -62,6 +62,7 @@
   log.info('using', 'node@%s', process.version)
 
   process.on('uncaughtException', errorHandler)
+  process.on('unhandledRejection', errorHandler)
 
   if (conf.usage && npm.command !== 'help') {
     npm.argv.unshift(npm.command)

lib/utils/error-handler.js

@@ -187,11 +187,12 @@ function errorHandler (er) {
   log.verbose('npm ', 'v' + npm.version)
 
   ;[
+    'code',
+    'syscall',
     'file',
     'path',
-    'code',
-    'errno',
-    'syscall'
+    'dest',
+    'errno'
   ].forEach(function (k) {
     var v = er[k]
     if (v) log.error(k, v)

lib/utils/error-message.js

@@ -2,6 +2,7 @@
 var npm = require('../npm.js')
 var util = require('util')
 var nameValidator = require('validate-npm-package-name')
+var npmlog = require('npmlog')
 
 module.exports = errorMessage
 
@@ -33,18 +34,42 @@ function errorMessage (er) {
 
     case 'EACCES':
     case 'EPERM':
-      short.push(['', er])
-      detail.push([
-        '',
-        [
-          '\nThe operation was rejected by your operating system.',
-          (process.platform === 'win32'
-            ? 'It\'s possible that the file was already in use (by a text editor or antivirus),\nor that you lack permissions to access it.'
-            : 'It is likely you do not have the permissions to access this file as the current user'),
-          '\nIf you believe this might be a permissions issue, please double-check the',
-          'permissions of the file and its containing directories, or try running',
-          'the command again as root/Administrator (though this is not recommended).'
-        ].join('\n')])
+      const isCachePath = typeof er.path === 'string' &&
+        er.path.startsWith(npm.config.get('cache'))
+      const isCacheDest = typeof er.dest === 'string' &&
+        er.dest.startsWith(npm.config.get('cache'))
+
+      const isWindows = process.platform === 'win32'
+
+      if (!isWindows && (isCachePath || isCacheDest)) {
+        // user probably doesn't need this, but still add it to the debug log
+        npmlog.verbose(er.stack)
+        short.push([
+          '',
+          [
+            '',
+            'Your cache folder contains root-owned files, due to a bug in',
+            'previous versions of npm which has since been addressed.',
+            '',
+            'To permanently fix this problem, please run:',
+            `  sudo chown -R ${process.getuid()}:${process.getgid()} ${JSON.stringify(npm.config.get('cache'))}`
+          ].join('\n')
+        ])
+      } else {
+        short.push(['', er])
+        detail.push([
+          '',
+          [
+            '\nThe operation was rejected by your operating system.',
+            (process.platform === 'win32'
+              ? 'It\'s possible that the file was already in use (by a text editor or antivirus),\n' +
+                'or that you lack permissions to access it.'
+              : 'It is likely you do not have the permissions to access this file as the current user'),
+            '\nIf you believe this might be a permissions issue, please double-check the',
+            'permissions of the file and its containing directories, or try running',
+            'the command again as root/Administrator.'
+          ].join('\n')])
+      }
       break
 
     case 'ELIFECYCLE':

test/tap/cache-eacces-error-message.js

@@ -0,0 +1,38 @@
+const npm = require('../../lib/npm.js')
+const t = require('tap')
+
+if (process.platform === 'win32') {
+  t.plan(0, 'this is a unix-only thing')
+  process.exit(0)
+}
+
+const errorMessage = require('../../lib/utils/error-message.js')
+
+const common = require('../common-tap.js')
+
+t.plan(1)
+
+npm.load({ cache: common.cache }, () => {
+  npm.config.set('cache', common.cache)
+  const er = new Error('access is e, i am afraid')
+  er.code = 'EACCES'
+  er.errno = -13
+  er.path = common.cache + '/src'
+  er.dest = common.cache + '/to'
+
+  t.match(errorMessage(er), {
+    summary: [
+      [
+        '',
+        new RegExp('\n' +
+          'Your cache folder contains root-owned files, due to a bug in\n' +
+          'previous versions of npm which has since been addressed.\n' +
+          '\n' +
+          'To permanently fix this problem, please run:\n' +
+          '  sudo chown -R [0-9]+:[0-9]+ ".*npm_cache_cache-eacces-error-message"'
+        )
+      ]
+    ],
+    detail: []
+  }, 'get the helpful error message')
+})