test: Ensure optional status is saved to lock file

test/tap/save-optional.js

@@ -0,0 +1,81 @@
+'use strict'
+const path = require('path')
+const test = require('tap').test
+const mr = require('npm-registry-mock')
+const Tacks = require('tacks')
+const fs = require('fs')
+const File = Tacks.File
+const Dir = Tacks.Dir
+const common = require('../common-tap.js')
+
+const basedir = path.join(__dirname, path.basename(__filename, '.js'))
+const testdir = path.join(basedir, 'testdir')
+const cachedir = path.join(basedir, 'cache')
+const globaldir = path.join(basedir, 'global')
+const tmpdir = path.join(basedir, 'tmp')
+
+const conf = {
+  cwd: testdir,
+  stdio: [0, 1, 2],
+  env: Object.assign({}, process.env, {
+    npm_config_cache: cachedir,
+    npm_config_tmp: tmpdir,
+    npm_config_prefix: globaldir,
+    npm_config_registry: common.registry,
+    npm_config_loglevel: 'silly'
+  })
+}
+
+let server
+const fixture = new Tacks(Dir({
+  cache: Dir(),
+  global: Dir(),
+  tmp: Dir(),
+  testdir: Dir({
+    example: Dir({
+      'package.json': File({
+        name: 'example',
+        version: '1.0.0'
+      })
+    }),
+    'package.json': File({
+      name: 'save-optional',
+      version: '1.0.0'
+    })
+  })
+}))
+
+function setup () {
+  cleanup()
+  fixture.create(basedir)
+}
+
+function cleanup () {
+  fixture.remove(basedir)
+}
+
+test('setup', function (t) {
+  setup()
+  mr({port: common.port, throwOnUnmatched: true}, function (err, s) {
+    if (err) throw err
+    server = s
+    t.done()
+  })
+})
+
+test('example', function (t) {
+  common.npm(['install', '-O', '--package-lock-only', 'file:example'], conf, function (err, code) {
+    if (err) throw err
+    t.is(code, 0, 'command ran ok')
+    const plock = JSON.parse(fs.readFileSync(`${testdir}/package-lock.json`))
+    t.like(plock, { dependencies: { example: { optional: true } } }, 'optional status saved')
+    // your assertions here
+    t.done()
+  })
+})
+
+test('cleanup', function (t) {
+  server.close()
+  cleanup()
+  t.done()
+})