From 43906c71e7bf2a09af2152cf48227eaf35f0b8ce Mon Sep 17 00:00:00 2001
From: Sameer Srivastava <sameer.srivastava@nearform.com>
Date: Fri, 29 Oct 2021 18:40:35 +0530
Subject: [PATCH] Fixes issue with nested keys (#1198)

* fix: fixes issue with nested keys

* chore: use strictSame in nested key test
---
 lib/tools.js       |  2 +-
 test/basic.test.js | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/lib/tools.js b/lib/tools.js
index 8fbcca977..f32fe53a6 100644
--- a/lib/tools.js
+++ b/lib/tools.js
@@ -173,7 +173,7 @@ function asJson (obj, msg, num, time) {
     }
   }
 
-  if (this[nestedKeySym]) {
+  if (this[nestedKeySym] && propStr) {
     // place all the obj properties under the specified key
     // the nested key is already formatted from the constructor
     return data + this[nestedKeyStrSym] + propStr.slice(1) + '}' + msgStr + end
diff --git a/test/basic.test.js b/test/basic.test.js
index 4eaa97174..6995431c2 100644
--- a/test/basic.test.js
+++ b/test/basic.test.js
@@ -712,3 +712,21 @@ test('correctly log number', async (t) => {
   const { msg } = await once(stream, 'data')
   t.equal(msg, 42)
 })
+
+test('nestedKey should not be used for non-objects', async ({ strictSame }) => {
+  const stream = sink()
+  const message = 'hello'
+  const nestedKey = 'stuff'
+  const instance = pino({
+    nestedKey
+  }, stream)
+  instance.info(message)
+  const result = await once(stream, 'data')
+  delete result.time
+  strictSame(result, {
+    pid,
+    hostname,
+    level: 30,
+    msg: message
+  })
+})