test: fix install check for optional deps

test/tap/install-optional-dep-identification.js

@@ -0,0 +1,50 @@
+'use strict'
+var path = require('path')
+var fs = require('graceful-fs')
+var mkdirp = require('mkdirp')
+var rimraf = require('rimraf')
+var test = require('tap').test
+var common = require('../common-tap.js')
+
+var base = path.join(__dirname, path.basename(__filename, '.js'))
+var moduleDir = path.join(base, 'example')
+var moduleJson = {
+  name: 'example',
+  version: '1.0.0',
+  optionalDependencies: {
+    'aws-sdk': 'latest'
+  }
+}
+
+function setup () {
+  cleanup()
+  mkdirp.sync(moduleDir)
+  fs.writeFileSync(path.join(moduleDir, 'package.json'), JSON.stringify(moduleJson))
+}
+
+function cleanup () {
+  rimraf.sync(base)
+}
+
+test('setup', function (t) {
+  setup()
+  t.end()
+})
+
+test('optional dependency identification', function (t) {
+  common.npm(
+    ['install', '--no-optional'],
+    {cwd: moduleDir},
+    function (er, code, stdout, stderr) {
+      t.is(code, 0, 'no error code')
+      t.is(stderr, '', 'no error output')
+      t.notOk(fs.existsSync(path.join(moduleDir, 'node_modules')), 'did not install anything')
+      t.end()
+    }
+  )
+})
+
+test('cleanup', function (t) {
+  cleanup()
+  t.end()
+})