added lastTime meta parameter (pinojs#385)

docs/API.md

@@ -637,6 +637,8 @@ should be set:
 * the last logging level as `stream.lastLevel`
 * the last logging message as `stream.lastMsg`
 * the last logging object as `stream.lastObj`
+* the last time as `stream.lastTime`, which will be the partial string returned
+  by the time function.
 * the last logger instance as `stream.lastLogger` (to support child
   loggers)
 

pino.js

@@ -129,12 +129,12 @@ Object.defineProperty(
   {value: LOG_VERSION}
 )
 
-function asJson (obj, msg, num) {
+function asJson (obj, msg, num, time) {
   // to catch both null and undefined
   var hasObj = obj !== undefined && obj !== null
   var objError = hasObj && obj instanceof Error
   msg = !msg && objError ? obj.message : msg || undefined
-  var data = this._lscache[num] + this.time()
+  var data = this._lscache[num] + time
   if (msg !== undefined) {
     // JSON.stringify is safe here
     data += this.messageKeyString + JSON.stringify('' + msg)
@@ -208,13 +208,15 @@ Object.defineProperty(pinoPrototype, 'child', {
 })
 
 function pinoWrite (obj, msg, num) {
-  var s = this.asJson(obj, msg, num)
+  var t = this.time()
+  var s = this.asJson(obj, msg, num, t)
   var stream = this.stream
   if (this.cache === null) {
     if (stream[needsMetadata]) {
       stream.lastLevel = num
       stream.lastMsg = msg
       stream.lastObj = obj
+      stream.lastTime = t.slice(8)
       stream.lastLogger = this // for child loggers
     }
     stream.write(flatstr(s))

test/metadata.test.js

@@ -9,7 +9,7 @@ var pid = process.pid
 var hostname = os.hostname()
 
 test('metadata works', function (t) {
-  t.plan(6)
+  t.plan(7)
   var dest = sink(function (chunk, enc, cb) {
     t.ok(new Date(chunk.time) <= new Date(), 'time is greater than Date.now()')
     delete chunk.time
@@ -22,12 +22,14 @@ test('metadata works', function (t) {
       v: 1
     })
   })
+  var now = Date.now()
   var instance = pino({}, {
     [Symbol.for('needsMetadata')]: true,
     write: function (chunk) {
       t.equal(instance, this.lastLogger)
       t.equal(30, this.lastLevel)
       t.equal('a msg', this.lastMsg)
+      t.ok(Number(this.lastTime) >= now)
       t.deepEqual({ hello: 'world' }, this.lastObj)
       dest.write(chunk)
     }