fix: twice customProps (#288)

* fix: twice customPropBindings

* Add unit test for twice customPropBindings

* Remove case insensitive in match regex

logger.js

@@ -1,6 +1,6 @@
 'use strict'
 
-const pino = require('pino')
+const { pino, symbols: { stringifySym, chindingsSym } } = require('pino')
 const serializers = require('pino-std-serializers')
 const getCallerFile = require('get-caller-file')
 const startTime = Symbol('startTime')
@@ -103,7 +103,11 @@ function pinoLogger (opts, stream) {
 
     const customPropBindings = (typeof customProps === 'function') ? customProps(req, res) : customProps
     if (customPropBindings) {
-      log = logger.child(customPropBindings)
+      const customPropBindingStr = logger[stringifySym](customPropBindings).replace(/[{}]/g, '')
+      const customPropBindingsStr = logger[chindingsSym]
+      if (!customPropBindingsStr.includes(customPropBindingStr)) {
+        log = logger.child(customPropBindings)
+      }
     }
 
     if (err || res.err || res.statusCode >= 500) {

test/test.js

@@ -1285,6 +1285,30 @@ test('uses custom request properties to log additional attributes; custom props
   })
 })
 
+test('uses custom request properties and once customProps', function (t) {
+  const dest = split()
+
+  function customPropsHandler (req, res) {
+    return {
+      key1: 'value1'
+    }
+  }
+
+  const logger = pinoHttp({
+    customProps: customPropsHandler
+  }, dest)
+
+  setup(t, logger, function (err, server) {
+    t.error(err)
+    doGet(server)
+  })
+
+  dest.on('data', function (line) {
+    t.equal(line.match(/key1/g).length, 1, 'once customProps')
+    t.end()
+  })
+})
+
 test('dont pass custom request properties to log additional attributes', function (t) {
   const dest = split(JSON.parse)
   const logger = pinoHttp({