doctor: add new subcommand

This command will diagnose user's environment and let
the user know some recommended solutions if they
potentially have any problems related to npm.

Credit: @watilde
Reviewed-By: @othiym23
Reviewed-By: @iarna
PR-URL: npm/npm#14582
Fixes: npm#6756

doc/cli/npm-doctor.md

@@ -0,0 +1,44 @@
+npm-doctor(1) -- Check your environments
+========================================================
+
+## SYNOPSIS
+
+    npm doctor
+
+## DESCRIPTION
+
+npm command is just a single command, but depends on several things outside
+the code base. Broadly speaking, it is the following three types:
+
++ Technology stack: Node.js, git
++ Registry: `registry.npmjs.com`
++ Files: `node_modules` in local/global, cached files in `npm config get cache`
+
+Without all of these working properly, the npm command will not work properly.
+Many issue reports that arrive under us are often attributable to things that
+are outside the code base as described above, and it is necessary to confirm
+that this is correctly set with one command would help you solve your issue.
+Also, in addition to this, there are also very many issue reports due to using
+old versions of npm. Since npm is constantly improving, in every aspect the
+`latest` npm is better than the old version(it should be, and we are trying).
+
+From the above reasons, `npm doctor` will investigate the following items in
+your environment and if there are any other recommended settings, it will
+display the recommended example.
+
+|What to check|What we recommend|
+|---|---|
+|`npm ping`|It must be able to communicate with the registry|
+|`npm -v`|It is preferable that the latest version of LTS is used|
+|`node -v`|It is preferable that the latest version of LTS is used|
+|`npm config get registry`|In order not to consider exceptions, it is better to set default values `registry.npmjs.org`|
+|`which git`|Git has to be installed|
+|`Perms check on cached files`|All cached module files must be readable.|
+|`Perms check on global node_modules`|All global module files must be executable.|
+|`Perms check on local node_modules`|All local module files must be executable.|
+|`Checksum cached files`|All cached files must not be broken|
+
+## SEE ALSO
+
+* npm-bugs(1)
+* npm-help(1)

lib/config/cmd-list.js

@@ -98,7 +98,8 @@ var cmdList = [
   'start',
   'restart',
   'run-script',
-  'completion'
+  'completion',
+  'doctor'
 ]
 
 var plumbing = [

lib/doctor.js

@@ -0,0 +1,109 @@
+var path = require('path')
+var chain = require('slide').chain
+var table = require('text-table')
+var color = require('ansicolors')
+var styles = require('ansistyles')
+var semver = require('semver')
+var npm = require('./npm.js')
+var log = require('npmlog')
+var ansiTrim = require('./utils/ansi-trim.js')
+var output = require('./utils/output.js')
+var defaultRegistry = require('./config/defaults.js').defaults.registry
+var checkPing = require('./doctor/check-ping.js')
+var getGitPath = require('./doctor/get-git-path.js')
+var checksumCachedFiles = require('./doctor/checksum-cached-files.js')
+var checkFilesPermission = require('./doctor/check-files-permission.js')
+var getLatestNodejsVersion = require('./doctor/get-latest-nodejs-version.js')
+var getLatestNpmVersion = require('./doctor/get-latest-npm-version')
+var globalNodeModules = path.join(npm.config.globalPrefix, 'lib', 'node_modules')
+var localNodeModules = path.join(npm.config.localPrefix, 'node_modules')
+
+module.exports = doctor
+
+doctor.usage = 'npm doctor'
+
+function doctor (args, silent, cb) {
+  args = args || {}
+  if (typeof cb !== 'function') {
+    cb = silent
+    silent = false
+  }
+
+  var actionsToRun = [
+    [checkPing],
+    [getLatestNpmVersion],
+    [getLatestNodejsVersion, args['node-url']],
+    [getGitPath],
+    [checkFilesPermission, npm.cache, 6],
+    [checkFilesPermission, globalNodeModules, 4],
+    [checkFilesPermission, localNodeModules, 6],
+    [checksumCachedFiles]
+  ]
+
+  log.info('doctor', 'Running checkup')
+  chain(actionsToRun, function (stderr, stdout) {
+    if (stderr && stderr.message !== 'not found: git') return cb(stderr)
+    var outHead = ['Check', 'Value', 'Recommendation']
+    var list = makePretty(stdout)
+    var outBody = list
+
+    if (npm.color) {
+      outHead = outHead.map(function (item) {
+        return styles.underline(item)
+      })
+      outBody = outBody.map(function (item) {
+        if (item[2]) {
+          item[0] = color.red(item[0])
+          item[2] = color.magenta(item[2])
+        }
+        return item
+      })
+    }
+
+    var outTable = [outHead].concat(outBody)
+    var tableOpts = {
+      stringLength: function (s) { return ansiTrim(s).length }
+    }
+
+    if (!silent) output(table(outTable, tableOpts))
+
+    cb(null, list)
+  })
+}
+
+function makePretty (p) {
+  var ping = p[0] ? 'ok' : 'notOk'
+  var npmLTS = p[1]
+  var nodeLTS = p[2].replace('v', '')
+  var whichGit = p[3] || 'not installed'
+  var readbleCaches = p[4] ? 'ok' : 'notOk'
+  var executableGlobalModules = p[5] ? 'ok' : 'notOk'
+  var executableLocalModules = p[6] ? 'ok' : 'notOk'
+  var checksumCachedFiles = p[7] ? 'ok' : 'notOk'
+  var npmV = npm.version
+  var nodeV = process.version.replace('v', '')
+  var registry = npm.config.get('registry')
+  var list = [
+    ['npm ping', ping],
+    ['npm -v', 'v' + npmV],
+    ['node -v', 'v' + nodeV],
+    ['npm config get registry', registry],
+    ['which git', whichGit],
+    ['Perms check on cached files', readbleCaches],
+    ['Perms check on global node_modules', executableGlobalModules],
+    ['Perms check on local node_modules', executableLocalModules],
+    ['Checksum cached files', checksumCachedFiles]
+  ]
+
+  if (ping !== 'ok') list[0][2] = 'Check your internet connection'
+  if (!semver.satisfies(npmV, '>=' + npmLTS)) list[1][2] = 'Use npm v' + npmLTS
+  if (!semver.satisfies(nodeV, '>=' + nodeLTS)) list[2][2] = 'Use node v' + nodeLTS
+  if (registry !== defaultRegistry) list[3][2] = 'Try `npm config set ' + defaultRegistry
+  if (whichGit === 'not installed') list[4][2] = 'Install git'
+  if (readbleCaches !== 'ok') list[5][2] = 'Check the permission of your files in ' + npm.config.get('cache')
+  if (executableGlobalModules !== 'ok') list[6][2] = 'Check the permission of your files in ' + globalNodeModules
+  if (executableLocalModules !== 'ok') list[7][2] = 'Check the permission of your files in ' + localNodeModules
+  if (checksumCachedFiles !== 'ok') list[8][2] = 'You have some broken packages in your cache'
+
+  return list
+}

lib/doctor/check-files-permission.js

@@ -0,0 +1,55 @@
+var fs = require('fs')
+var path = require('path')
+var getUid = require('uid-number')
+var chain = require('slide').chain
+var log = require('npmlog')
+var npm = require('../npm.js')
+var fileCompletion = require('../utils/completion/file-completion.js')
+
+function checkFilesPermission (root, mask, cb) {
+  if (process.platform === 'win32') return cb(null, true)
+  getUid(npm.config.get('user'), npm.config.get('group'), function (e, uid, gid) {
+    if (e) {
+      tracker.finish()
+      tracker.warn('checkFilePermissions', 'Error looking up user and group:', e)
+      return cb(e)
+    }
+    var tracker = log.newItem('checkFilePermissions', 1)
+    tracker.info('checkFilePermissions', 'Building file list of ' + root)
+    fileCompletion(root, '.', Infinity, function (e, files) {
+      if (e) {
+        tracker.warn('checkFilePermissions', 'Error building file list:', e)
+        tracker.finish()
+        return cb(e)
+      }
+      tracker.addWork(files.length)
+      tracker.completeWork(1)
+      chain(files.map(andCheckFile), function (er) {
+        tracker.finish()
+        cb(null, !er)
+      })
+      function andCheckFile (f) {
+        return [checkFile, f]
+      }
+      function checkFile (f, next) {
+        var file = path.join(root, f)
+        tracker.silly('checkFilePermissions', f)
+        fs.stat(file, function (e, stat) {
+          tracker.completeWork(1)
+          if (e) return next(e)
+          if (!stat.isFile()) return next()
+          var mode = stat.mode
+          var isGroup = stat.gid ? stat.gid === gid : true
+          var isUser = stat.uid ? stat.uid === uid : true
+          if ((mode & parseInt('000' + mask, 8))) return next()
+          if ((isGroup && mode & parseInt('00' + mask + '0', 8))) return next()
+          if ((isUser && mode & parseInt('0' + mask + '00', 8))) return next()
+          tracker.error('checkFilePermissions', 'Missing permissions on (' + isGroup + ', ' + isUser + ', ' + mode + ')', file)
+          return next(new Error('Missing permissions for ' + file))
+        })
+      }
+    })
+  })
+}
+
+module.exports = checkFilesPermission

lib/doctor/check-ping.js

@@ -0,0 +1,13 @@
+var log = require('npmlog')
+var ping = require('../ping.js')
+
+function checkPing (cb) {
+  var tracker = log.newItem('checkPing', 1)
+  tracker.info('checkPing', 'Pinging registry')
+  ping({}, true, function (err, pong) {
+    tracker.finish()
+    cb(err, pong)
+  })
+}
+
+module.exports = checkPing

lib/doctor/checksum-cached-files.js

@@ -0,0 +1,62 @@
+var crypto = require('crypto')
+var fs = require('fs')
+var path = require('path')
+var chain = require('slide').chain
+var log = require('npmlog')
+var npm = require('../npm')
+var fileCompletion = require('../utils/completion/file-completion.js')
+
+function checksum (str) {
+  return crypto
+    .createHash('sha1')
+    .update(str, 'utf8')
+    .digest('hex')
+}
+
+function checksumCachedFiles (cb) {
+  var tracker = log.newItem('checksumCachedFiles', 1)
+  tracker.info('checksumCachedFiles', 'Building file list of ' + npm.cache)
+  fileCompletion(npm.cache, '.', Infinity, function (e, files) {
+    if (e) {
+      tracker.finish()
+      return cb(e)
+    }
+    tracker.addWork(files.length)
+    tracker.completeWork(1)
+    chain(files.map(andChecksumFile), function (er) {
+      tracker.finish()
+      cb(null, !er)
+    })
+    function andChecksumFile (f) {
+      return [function (next) { process.nextTick(function () { checksumFile(f, next) }) }]
+    }
+    function checksumFile (f, next) {
+      var file = path.join(npm.cache, f)
+      tracker.silly('checksumFile', f)
+      if (!/.tgz$/.test(file)) {
+        tracker.completeWork(1)
+        return next()
+      }
+      fs.readFile(file, function (err, tgz) {
+        tracker.completeWork(1)
+        if (err) return next(err)
+        try {
+          var pkgJSON = fs.readFileSync(path.join(path.dirname(file), 'package/package.json'))
+        } catch (e) {
+          return next() // no package.json in cche is ok
+        }
+        try {
+          var pkg = JSON.parse(pkgJSON)
+          var shasum = (pkg.dist && pkg.dist.shasum) || pkg._shasum
+          var actual = checksum(tgz)
+          if (actual !== shasum) return next(new Error('Checksum mismatch on ' + file + ', expected: ' + shasum + ', got: ' + shasum))
+          return next()
+        } catch (e) {
+          return next(new Error('Error parsing JSON in ' + file + ': ' + e))
+        }
+      })
+    }
+  })
+}
+
+module.exports = checksumCachedFiles

lib/doctor/get-git-path.js

@@ -0,0 +1,13 @@
+var log = require('npmlog')
+var which = require('which')
+
+function getGitPath (cb) {
+  var tracker = log.newItem('getGitPath', 1)
+  tracker.info('getGitPath', 'Finding git in your PATH')
+  which('git', function (err, path) {
+    tracker.finish()
+    cb(err, path)
+  })
+}
+
+module.exports = getGitPath

lib/doctor/get-latest-nodejs-version.js

@@ -0,0 +1,26 @@
+var log = require('npmlog')
+var request = require('request')
+
+function getLatestNodejsVersion (url, cb) {
+  var tracker = log.newItem('getLatestNodejsVersion', 1)
+  tracker.info('getLatestNodejsVersion', 'Getting Node.js release information')
+  var version = ''
+  url = url || 'https://nodejs.org/dist/index.json'
+  request(url, function (e, res, index) {
+    tracker.finish()
+    if (e) return cb(e)
+    if (res.statusCode !== 200) {
+      return cb(new Error('Status not 200, ' + res.statusCode))
+    }
+    try {
+      JSON.parse(index).forEach(function (item) {
+        if (item.lts && item.version > version) version = item.version
+      })
+      cb(null, version)
+    } catch (e) {
+      cb(e)
+    }
+  })
+}
+
+module.exports = getLatestNodejsVersion

lib/doctor/get-latest-npm-version.js

@@ -0,0 +1,13 @@
+var log = require('npmlog')
+var fetchPackageMetadata = require('../fetch-package-metadata')
+
+function getLatestNpmVersion (cb) {
+  var tracker = log.newItem('getLatestNpmVersion', 1)
+  tracker.info('getLatestNpmVersion', 'Getting npm package information')
+  fetchPackageMetadata('npm@latest', '.', function (e, d) {
+    tracker.finish()
+    cb(e, d.version)
+  })
+}
+
+module.exports = getLatestNpmVersion