From 1c34d792e4940d066fa0318c15af54b2e76aaf25 Mon Sep 17 00:00:00 2001
From: Matteo Collina <hello@matteocollina.com>
Date: Wed, 8 Aug 2018 15:01:51 +0200
Subject: [PATCH] If a value is undefined, we need to skip the key as well

---
 index.js           | 8 +++-----
 test/basic.test.js | 3 +--
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/index.js b/index.js
index 0d6d1afd..371bd6f3 100644
--- a/index.js
+++ b/index.js
@@ -196,10 +196,6 @@ 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]
@@ -248,7 +244,9 @@ module.exports = function prettyFactory (options) {
             }
           }
         } else if (filteredKeys.indexOf(keys[i]) < 0) {
-          result += IDENT + keys[i] + ': ' + joinLinesWithIndentation(JSON.stringify(value[keys[i]], null, 2)) + EOL
+          if (value[keys[i]] !== undefined) {
+            result += IDENT + keys[i] + ': ' + joinLinesWithIndentation(JSON.stringify(value[keys[i]], null, 2)) + EOL
+          }
         }
       }
 
diff --git a/test/basic.test.js b/test/basic.test.js
index c297a608..7295b8a6 100644
--- a/test/basic.test.js
+++ b/test/basic.test.js
@@ -443,8 +443,7 @@ test('basic prettifier tests', (t) => {
         const formatted = pretty(obj)
         t.is(
           formatted,
-          `[${epoch}] INFO (${pid} on ${hostname}): foo
-    a: undefined\n`
+          `[${epoch}] INFO (${pid} on ${hostname}): foo\n`
         )
         cb()
       }