From 186642ebdb7939b36809825fb2ef0fa71e5f6efa Mon Sep 17 00:00:00 2001
From: Matteo Collina <hello@matteocollina.com>
Date: Wed, 8 Aug 2018 14:44:28 +0200
Subject: [PATCH] Do not crash with a property that has value undefined

---
 index.js           |  4 ++++
 test/basic.test.js | 21 ++++++++++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index 53a07e84..0d6d1afd 100644
--- a/index.js
+++ b/index.js
@@ -196,6 +196,10 @@ module.exports = function prettyFactory (options) {
     return line
 
     function joinLinesWithIndentation (value) {
+      if (!value) {
+        return
+      }
+
       const lines = value.split(/\r?\n/)
       for (var i = 1; i < lines.length; i++) {
         lines[i] = IDENT + lines[i]
diff --git a/test/basic.test.js b/test/basic.test.js
index 6112d279..c297a608 100644
--- a/test/basic.test.js
+++ b/test/basic.test.js
@@ -22,7 +22,6 @@ test('basic prettifier tests', (t) => {
   t.afterEach((done) => {
     Date.now = Date.originalNow
     delete Date.originalNow
-
     done()
   })
 
@@ -433,5 +432,25 @@ test('basic prettifier tests', (t) => {
     t.is(formatted, `[${epoch}] INFO: hello world\n`)
   })
 
+  t.test('formats a line with an undefined field', (t) => {
+    t.plan(1)
+    const pretty = prettyFactory()
+    const log = pino({}, new Writable({
+      write (chunk, enc, cb) {
+        const obj = JSON.parse(chunk.toString())
+        // weird hack, but we should not crash
+        obj.a = undefined
+        const formatted = pretty(obj)
+        t.is(
+          formatted,
+          `[${epoch}] INFO (${pid} on ${hostname}): foo
+    a: undefined\n`
+        )
+        cb()
+      }
+    }))
+    log.info('foo')
+  })
+
   t.end()
 })