From 753666c7287de656f563ce25f76e05227ece8026 Mon Sep 17 00:00:00 2001
From: Richard Quadling <Richard.Quadling@DigiTickets.co.uk>
Date: Mon, 24 Dec 2018 14:21:28 +0000
Subject: [PATCH] generateMessage will always return a string.

---
 lib/Assert/Assertion.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/Assert/Assertion.php b/lib/Assert/Assertion.php
index 29bc3646..2e493a62 100644
--- a/lib/Assert/Assertion.php
+++ b/lib/Assert/Assertion.php
@@ -2589,9 +2589,9 @@ protected static function stringify($value)
      *
      * @param string|callable $message
      *
-     * @return string|null
+     * @return string
      */
-    protected static function generateMessage($message)
+    protected static function generateMessage($message): string
     {
         if (\is_callable($message)) {
             $traces = \debug_backtrace(0);
@@ -2618,6 +2618,6 @@ protected static function generateMessage($message)
             } // @codeCoverageIgnoreEnd
         }
 
-        return \is_null($message) ? null : (string) $message;
+        return (string) $message;
     }
 }