fix: adds support for printing number and boolean messageKey value type

index.js

@@ -162,7 +162,7 @@ function prettyFactory (options) {
       line += ':'
     }
 
-    if (prettifiedMessage) {
+    if (prettifiedMessage !== undefined) {
       if (line.length > 0) {
         line = `${line} ${prettifiedMessage}`
       } else {
@@ -186,7 +186,7 @@ function prettyFactory (options) {
       if (singleLine) line += EOL
       line += prettifiedErrorLog
     } else if (!hideObject) {
-      const skipKeys = [messageKey, levelKey, timestampKey].filter(key => typeof log[key] === 'string' || typeof log[key] === 'number')
+      const skipKeys = [messageKey, levelKey, timestampKey].filter(key => typeof log[key] === 'string' || typeof log[key] === 'number' || typeof log[key] === 'boolean')
       const prettifiedObject = prettifyObject({
         input: log,
         skipKeys,

lib/utils.js

@@ -280,7 +280,7 @@ function prettifyMessage ({ log, messageFormat, messageKey = MESSAGE_KEY, colori
     return colorizer.message(msg)
   }
   if (messageKey in log === false) return undefined
-  if (typeof log[messageKey] !== 'string') return undefined
+  if (typeof log[messageKey] !== 'string' && typeof log[messageKey] !== 'number' && typeof log[messageKey] !== 'boolean') return undefined
   return colorizer.message(log[messageKey])
 }
 

test/basic.test.js

@@ -118,6 +118,70 @@ test('basic prettifier tests', (t) => {
     log.info('foo')
   })
 
+  t.test('can print message key value when its a string', (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}): baz\n`
+        )
+        cb()
+      }
+    }))
+    log.info('baz')
+  })
+
+  t.test('can print message key value when its a number', (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}): 42\n`
+        )
+        cb()
+      }
+    }))
+    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()
+    const log = pino({}, new Writable({
+      write (chunk, enc, cb) {
+        const formatted = pretty(chunk.toString())
+        t.equal(
+          formatted,
+          `[${formattedEpoch}] INFO (${pid}): true\n`
+        )
+        cb()
+      }
+    }))
+    log.info(true)
+  })
+
   t.test('can use different message keys', (t) => {
     t.plan(1)
     const pretty = prettyFactory({ messageKey: 'bar' })