Print msg as an object if it is an object

index.js

@@ -153,7 +153,7 @@ module.exports = function prettyFactory (options) {
 
     line += ': '
 
-    if (log[messageKey]) {
+    if (log[messageKey] && typeof log[messageKey] === 'string') {
       line += color.message(log[messageKey])
     }
 
@@ -190,7 +190,7 @@ module.exports = function prettyFactory (options) {
         }
       }
     } else {
-      line += filterObjects(log, messageKey, errorLikeObjectKeys)
+      line += filterObjects(log, typeof log[messageKey] === 'string' ? messageKey : undefined, errorLikeObjectKeys)
     }
 
     return line
@@ -207,7 +207,11 @@ module.exports = function prettyFactory (options) {
       errorLikeObjectKeys = errorLikeObjectKeys || []
 
       const keys = Object.keys(value)
-      const filteredKeys = [messageKey]
+      const filteredKeys = []
+
+      if (messageKey) {
+        filteredKeys.push(messageKey)
+      }
 
       if (excludeStandardKeys !== false) {
         Array.prototype.push.apply(filteredKeys, standardKeys)

test/basic.test.js

@@ -5,7 +5,16 @@ const os = require('os')
 const test = require('tap').test
 const pino = require('pino')
 const dateformat = require('dateformat')
-const prettyFactory = require('../')
+const _prettyFactory = require('../')
+
+function prettyFactory (opts) {
+  if (!opts) {
+    opts = { colorize: false }
+  } else if (!opts.hasOwnProperty('colorize')) {
+    opts.colorize = false
+  }
+  return _prettyFactory(opts)
+}
 
 // All dates are computed from 'Fri, 30 Mar 2018 17:35:28 GMT'
 const epoch = 1522431328992
@@ -451,5 +460,30 @@ test('basic prettifier tests', (t) => {
     log.info('foo')
   })
 
+  t.test('prettifies msg object', (t) => {
+    t.plan(6)
+    const expectedLines = [
+      '    msg: {',
+      '      "b": {',
+      '        "c": "d"',
+      '      }',
+      '    }'
+    ]
+    const pretty = prettyFactory()
+    const log = pino({}, new Writable({
+      write (chunk, enc, cb) {
+        const formatted = pretty(chunk.toString())
+        const lines = formatted.split('\n')
+        t.is(lines.length, expectedLines.length + 2)
+        lines.shift(); lines.pop()
+        for (var i = 0; i < lines.length; i += 1) {
+          t.is(lines[i], expectedLines[i])
+        }
+        cb()
+      }
+    }))
+    log.info({ msg: { b: { c: 'd' } } })
+  })
+
   t.end()
 })