fix: delay plugin loading until next tick (#177)

* fix: delay plugin loading until next tick

* move `loadPluginNextTick` function alongside `loadPlugin` and add comment

* refactor loadPluginNextTick to use a bound function rather than an anonymous closure

* remove top-level FS read from unit test that was preventing the bug from occurring

* add additional test case

plugin.js

@@ -49,7 +49,7 @@ function Plugin (parent, func, optsOrFunc, isAfter, timeout) {
   this.timeout = timeout === undefined ? parent._timeout : timeout
   this.name = getName(func, optsOrFunc)
   this.isAfter = isAfter
-  this.q = fastq(parent, loadPlugin, 1)
+  this.q = fastq(parent, loadPluginNextTick, 1)
   this.q.pause()
   this._error = null
   this.loaded = false
@@ -245,6 +245,13 @@ Plugin.prototype.finish = function (err, cb) {
   this.q.resume()
 }
 
+// delays plugin loading until the next tick to ensure any bound `_after` callbacks have a chance
+// to run prior to executing the next plugin
+function loadPluginNextTick (toLoad, cb) {
+  const parent = this
+  process.nextTick(loadPlugin.bind(parent), toLoad, cb)
+}
+
 // loads a plugin
 function loadPlugin (toLoad, cb) {
   if (typeof toLoad.func.then === 'function') {

test/await-after.test.js

@@ -4,6 +4,8 @@ const { test } = require('tap')
 const boot = require('..')
 const { promisify } = require('util')
 const sleep = promisify(setTimeout)
+const fs = require('fs').promises
+const path = require('path')
 
 test('await after - nested plugins with same tick callbacks', async (t) => {
   const app = {}
@@ -306,6 +308,74 @@ test('await after complex scenario', async (t) => {
   }
 })
 
+test('without autostart and sync/async plugin mix', async (t) => {
+  const app = {}
+  boot(app, { autostart: false })
+  t.plan(21)
+
+  let firstLoaded = false
+  let secondLoaded = false
+  let thirdLoaded = false
+  let fourthLoaded = false
+
+  app.use(first)
+  await app.after()
+  t.ok(firstLoaded, 'first is loaded')
+  t.notOk(secondLoaded, 'second is not loaded')
+  t.notOk(thirdLoaded, 'third is not loaded')
+  t.notOk(fourthLoaded, 'fourth is not loaded')
+
+  app.use(second)
+  await app.after()
+  t.ok(firstLoaded, 'first is loaded')
+  t.ok(secondLoaded, 'second is loaded')
+  t.notOk(thirdLoaded, 'third is not loaded')
+  t.notOk(fourthLoaded, 'fourth is not loaded')
+
+  await sleep(10)
+
+  app.use(third)
+  await app.after()
+  t.ok(firstLoaded, 'first is loaded')
+  t.ok(secondLoaded, 'second is loaded')
+  t.ok(thirdLoaded, 'third is loaded')
+  t.notOk(fourthLoaded, 'fourth is not loaded')
+
+  app.use(fourth)
+  t.ok(firstLoaded, 'first is loaded')
+  t.ok(secondLoaded, 'second is loaded')
+  t.ok(thirdLoaded, 'third is loaded')
+  t.notOk(fourthLoaded, 'fourth is not loaded')
+
+  await app.after()
+  t.ok(firstLoaded, 'first is loaded')
+  t.ok(secondLoaded, 'second is loaded')
+  t.ok(thirdLoaded, 'third is loaded')
+  t.ok(fourthLoaded, 'fourth is loaded')
+
+  await app.ready()
+
+  async function first () {
+    firstLoaded = true
+  }
+
+  async function second () {
+    const contents = await fs.readFile(path.join(__dirname, 'fixtures', 'dummy.txt'), 'utf-8')
+    t.equal(contents, 'hello, world!')
+    secondLoaded = true
+  }
+
+  async function third () {
+    await sleep(10)
+    thirdLoaded = true
+  }
+
+  function fourth (server, opts, done) {
+    fourthLoaded = true
+    done()
+  }
+})
+
 test('without autostart', async (t) => {
   const app = {}
   boot(app, { autostart: false })

test/await-use.test.js

@@ -1,6 +1,8 @@
 'use strict'
 
 const { test } = require('tap')
+const { promisify } = require('util')
+const sleep = promisify(setTimeout)
 const boot = require('..')
 
 test('await use - nested plugins with same tick callbacks', async (t) => {
@@ -242,3 +244,29 @@ test('mixed await use and non-awaited use ', async (t) => {
     fourthLoaded = true
   }
 })
+
+test('await use - mix of same and future tick callbacks', async (t) => {
+  const app = {}
+  boot(app, { autostart: false })
+  let record = ''
+
+  t.plan(4)
+
+  await app.use(async function plugin0 () {
+    t.pass('plugin0 init')
+    record += 'plugin0|'
+  })
+  await app.use(async function plugin1 () {
+    t.pass('plugin1 init')
+    await sleep(500)
+    record += 'plugin1|'
+  })
+  await sleep(1)
+  await app.use(async function plugin2 () {
+    t.pass('plugin2 init')
+    await sleep(500)
+    record += 'plugin2|'
+  })
+  record += 'ready'
+  t.equal(record, 'plugin0|plugin1|plugin2|ready')
+})

test/fixtures/dummy.txt

@@ -0,0 +1 @@
+hello, world!