From ee1dc4042faab3599737f26cf7e5a36a2947f2a4 Mon Sep 17 00:00:00 2001
From: rjmohammad <rjmohammad@outlook.com>
Date: Sat, 1 Jul 2023 01:14:26 -0400
Subject: [PATCH] fix: checks for undefined specifically instead of falsey
 values

---
 index.js           |  2 +-
 test/basic.test.js | 22 +++++++++++++++++++---
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/index.js b/index.js
index 000a873c..41eb7602 100644
--- a/index.js
+++ b/index.js
@@ -162,7 +162,7 @@ function prettyFactory (options) {
       line += ':'
     }
 
-    if (prettifiedMessage) {
+    if (prettifiedMessage !== undefined) {
       if (line.length > 0) {
         line = `${line} ${prettifiedMessage}`
       } else {
diff --git a/test/basic.test.js b/test/basic.test.js
index 8514c416..9986811c 100644
--- a/test/basic.test.js
+++ b/test/basic.test.js
@@ -133,7 +133,7 @@ test('basic prettifier tests', (t) => {
     }))
     log.info('baz')
   })
-  
+
   t.test('can print message key value when its a number', (t) => {
     t.plan(1)
     const pretty = prettyFactory()
@@ -149,7 +149,23 @@ test('basic prettifier tests', (t) => {
     }))
     log.info(42)
   })
-  
+
+  t.test('can print message key value when its a Number(0)', (t) => {
+    t.plan(1)
+    const pretty = prettyFactory()
+    const log = pino({}, new Writable({
+      write (chunk, enc, cb) {
+        const formatted = pretty(chunk.toString())
+        t.equal(
+          formatted,
+          `[${formattedEpoch}] INFO (${pid}): 0\n`
+        )
+        cb()
+      }
+    }))
+    log.info(0)
+  })
+
   t.test('can print message key value when its a boolean', (t) => {
     t.plan(1)
     const pretty = prettyFactory()
@@ -165,7 +181,7 @@ test('basic prettifier tests', (t) => {
     }))
     log.info(true)
   })
-  
+
   t.test('can use different message keys', (t) => {
     t.plan(1)
     const pretty = prettyFactory({ messageKey: 'bar' })