From 2d1fbbe4232a5070f1b60b33a238a614a4a3b385 Mon Sep 17 00:00:00 2001
From: Haralan Dobrev <hkdobrev@gmail.com>
Date: Mon, 14 Nov 2016 23:19:45 +0200
Subject: [PATCH] Make SlackRecord::stringify() work without a line formatter

---
 src/Monolog/Handler/Slack/SlackRecord.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/Monolog/Handler/Slack/SlackRecord.php b/src/Monolog/Handler/Slack/SlackRecord.php
index cc8493c1..4b370b3b 100644
--- a/src/Monolog/Handler/Slack/SlackRecord.php
+++ b/src/Monolog/Handler/Slack/SlackRecord.php
@@ -216,10 +216,14 @@ class SlackRecord
      * Stringifies an array of key/value pairs to be used in attachment fields
      *
      * @param  array  $fields
-     * @return string
+     * @return string|null
      */
     public function stringify($fields)
     {
+        if (!$this->lineFormatter) {
+            return null;
+        }
+
         $string = '';
         foreach ($fields as $var => $val) {
             $string .= $var.': '.$this->lineFormatter->stringify($val)." | ";