test: add npm self installation test

Credit: @iarna
PR-URL: npm/npm#11292
Reviewed-By: @zkat

.npmignore

@@ -7,6 +7,7 @@ npm-debug.log
 /test/packages/npm-test-depends-on-spark/which-spark.log
 /test/packages/test-package/random-data.txt
 /test/root
+/test/npm_cache
 node_modules/marked
 node_modules/ronn
 node_modules/tap

test/tap/legacy-npm-self-install.js

@@ -0,0 +1,106 @@
+'use strict'
+var test = require('tap').test
+var fs = require('graceful-fs')
+var common = require('../common-tap.js')
+var path = require('path')
+var rimraf = require('rimraf')
+var mkdirp = require('mkdirp')
+var npmpath = path.resolve(__dirname, '../..')
+var basepath = path.resolve(__dirname, path.basename(__filename, '.js'))
+var globalpath = path.resolve(basepath, 'global')
+var extend = Object.assign || require('util')._extend
+var isWin32 = process.platform === 'win32'
+
+test('setup', function (t) {
+  setup()
+  t.done()
+})
+
+var tarball
+
+test('build-tarball', function (t) {
+  common.npm(['pack'], {cwd: npmpath, stdio: ['ignore', 'pipe', process.stderr]}, function (err, code, stdout) {
+    if (err) throw err
+    t.is(code, 0, 'pack went ok')
+    tarball = path.resolve(npmpath, stdout.trim().replace(/^(?:.|\n)*(?:^|\n)(.*?[.]tgz)$/, '$1'))
+    t.match(tarball, /[.]tgz$/, 'got a tarball')
+    t.done()
+  })
+})
+
+function exists () {
+  try {
+    fs.statSync(path.resolve.apply(null, arguments))
+    return true
+  } catch (ex) {
+    return false
+  }
+}
+
+test('npm-self-install', function (t) {
+  if (!tarball) return t.done()
+
+  var env = extend({}, process.env)
+  var pathsep = isWin32 ? ';' : ':'
+  env.npm_config_prefix = globalpath
+  env.npm_config_global = 'true'
+  env.npm_config_npat = 'false'
+  env.NODE_PATH = null
+  env.npm_config_user_agent = null
+  env.npm_config_color = 'always'
+  env.npm_config_progress = 'always'
+  var PATH = env.PATH.split(pathsep)
+  var binpath = isWin32 ? globalpath : path.join(globalpath, 'bin')
+  var cmdname = isWin32 ? 'npm.cmd' : 'npm'
+  PATH.unshift(binpath)
+  env.PATH = PATH.join(pathsep)
+
+  var opts = {cwd: basepath, env: env, stdio: ['ignore', 'ignore', process.stderr]}
+
+  common.npm(['install', '--ignore-scripts', tarball], opts, installCheckAndTest)
+  function installCheckAndTest (err, code) {
+    if (err) throw err
+    t.is(code, 0, 'install went ok')
+    t.is(exists(binpath, cmdname), true, 'binary was installed')
+    t.is(exists(globalpath, 'lib', 'node_modules', 'npm'), true, 'module path exists')
+    common.npm(['ls', '--json', '--depth=0'], {cwd: basepath, env: env}, lsCheckAndRemove)
+  }
+  function lsCheckAndRemove (err, code, stdout, stderr) {
+    t.ifError(err, 'npm test on array bin')
+    t.equal(code, 0, 'exited OK')
+    t.equal(stderr.trim(), '', 'no error output')
+    var installed = JSON.parse(stdout.trim())
+    t.is(Object.keys(installed.dependencies).length, 1, 'one thing installed')
+    t.is(path.resolve(globalpath, installed.dependencies.npm.from), tarball, 'and it was our npm tarball')
+    common.npm(['rm', 'npm'], {cwd: basepath, env: env, stdio: 'inherit'}, removeCheck)
+  }
+  function removeCheck (err, code) {
+    if (err) throw err
+    t.is(code, 0, 'remove went ok')
+    common.npm(['ls', '--json', '--depth=0'], {cwd: basepath, env: env}, andDone)
+  }
+  function andDone (err, code, stdout, stderr) {
+    if (err) throw err
+    t.is(code, 0, 'remove went ok')
+    t.equal(stderr.trim(), '', 'no error output')
+    var installed = JSON.parse(stdout.trim())
+    t.ok(!installed.dependencies || installed.dependencies.length === 0, 'nothing left')
+    t.is(exists(binpath, cmdname), false, 'binary was removed')
+    t.is(exists(globalpath, 'lib', 'node_modules', 'npm'), false, 'module was entirely removed')
+    t.done()
+  }
+})
+
+test('cleanup', function (t) {
+  cleanup()
+  t.done()
+})
+
+function setup () {
+  cleanup()
+  mkdirp.sync(globalpath)
+}
+
+function cleanup () {
+  rimraf.sync(basepath)
+}