Makes pinojs#711 mergable (pinojs#777)

* Log literal null values (fixes pinojs#706)

* When passing multiple parameters, omit null value

Co-authored-by: Nik <[email protected]>

Author: jsumners

example.js

@@ -31,5 +31,6 @@ pino.trace('this is a trace statement')
 pino.debug('this is a "debug" statement with "')
 
 pino.info(new Error('kaboom'))
+pino.info(null)
 
 pino.info(new Error('kaboom'), 'with', 'a', 'message')

lib/tools.js

@@ -28,15 +28,20 @@ function noop () {}
 
 function genLog (z) {
   return function LOG (o, ...n) {
-    if (typeof o === 'object' && o !== null) {
-      if (o.method && o.headers && o.socket) {
-        o = mapHttpRequest(o)
-      } else if (typeof o.setHeader === 'function') {
-        o = mapHttpResponse(o)
+    if (typeof o === 'object') {
+      if (o !== null) {
+        if (o.method && o.headers && o.socket) {
+          o = mapHttpRequest(o)
+        } else if (typeof o.setHeader === 'function') {
+          o = mapHttpResponse(o)
+        }
       }
       if (this[nestedKeySym]) o = { [this[nestedKeySym]]: o }
-      this[writeSym](o, format(null, n, this[formatOptsSym]), z)
-    } else this[writeSym](null, format(o, n, this[formatOptsSym]), z)
+      const formatParams = (o === null && n.length === 0) ? [null] : n
+      this[writeSym](o, format(null, formatParams, this[formatOptsSym]), z)
+    } else {
+      this[writeSym](null, format(o, n, this[formatOptsSym]), z)
+    }
   }
 }
 

test/levels.test.js

@@ -403,6 +403,36 @@ test('passes when creating a default value that exists in logger levels', async
   })
 })
 
+test('log null value when message is null', async ({ is }) => {
+  const expected = {
+    msg: null,
+    level: 30
+  }
+
+  const stream = sink()
+  const instance = pino(stream)
+  instance.level = 'info'
+  instance.info(null)
+
+  const result = await once(stream, 'data')
+  check(is, result, expected.level, expected.msg)
+})
+
+test('concatenate multiple params when base param is null', async ({ is }) => {
+  const expected = {
+    msg: 'a string',
+    level: 30
+  }
+
+  const stream = sink()
+  const instance = pino(stream)
+  instance.level = 'info'
+  instance.info(null, 'a', 'string')
+
+  const result = await once(stream, 'data')
+  check(is, result, expected.level, expected.msg)
+})
+
 test('fatal method sync-flushes the destination if sync flushing is available', async ({ pass, doesNotThrow, plan }) => {
   plan(2)
   const stream = sink()