From 2d6a2246f6d716444e1e0c8d7f4d46e6e15a84c5 Mon Sep 17 00:00:00 2001
From: Cemre Mengu <cemremengu@gmail.com>
Date: Fri, 8 Feb 2019 02:47:30 +0300
Subject: [PATCH] Add type check for onclose callback (#80)

---
 boot.js            |  5 +++++
 test/close.test.js | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/boot.js b/boot.js
index e3c5bd7..69cdf32 100644
--- a/boot.js
+++ b/boot.js
@@ -221,6 +221,11 @@ Boot.prototype.after = function (func) {
 Boot.prototype.onClose = function (func) {
   // this is used to distinguish between onClose and close handlers
   // because they share the same queue but must be called with different signatures
+
+  if (typeof func !== 'function') {
+    throw new Error('not a function')
+  }
+
   func[this._isOnCloseHandlerKey] = true
   this._closeQ.unshift(func, callback.bind(this))
 
diff --git a/test/close.test.js b/test/close.test.js
index 76f0e0a..198c53d 100644
--- a/test/close.test.js
+++ b/test/close.test.js
@@ -476,3 +476,14 @@ test('close with async onClose handlers', (t) => {
     })
   })
 })
+
+test('onClose callback must be a function', (t) => {
+  t.plan(1)
+
+  const app = boot()
+
+  app.use(function (server, opts, done) {
+    t.throws(() => app.onClose({}), { message: 'not a function' })
+    done()
+  })
+})