Fixed deprecation warnings about passing null as parameter

Author: derrabus

bin/simple-phpunit.php

@@ -151,9 +151,9 @@
 }
 
 $COMPOSER = file_exists($COMPOSER = $oldPwd.'/composer.phar')
-    || ($COMPOSER = rtrim('\\' === \DIRECTORY_SEPARATOR ? preg_replace('/[\r\n].*/', '', `where.exe composer.phar 2> NUL`) : `which composer.phar 2> /dev/null`))
-    || ($COMPOSER = rtrim('\\' === \DIRECTORY_SEPARATOR ? preg_replace('/[\r\n].*/', '', `where.exe composer 2> NUL`) : `which composer 2> /dev/null`))
-    || file_exists($COMPOSER = rtrim('\\' === \DIRECTORY_SEPARATOR ? `git rev-parse --show-toplevel 2> NUL` : `git rev-parse --show-toplevel 2> /dev/null`).\DIRECTORY_SEPARATOR.'composer.phar')
+    || ($COMPOSER = rtrim((string) ('\\' === \DIRECTORY_SEPARATOR ? preg_replace('/[\r\n].*/', '', `where.exe composer.phar 2> NUL`) : `which composer.phar 2> /dev/null`)))
+    || ($COMPOSER = rtrim((string) ('\\' === \DIRECTORY_SEPARATOR ? preg_replace('/[\r\n].*/', '', `where.exe composer 2> NUL`) : `which composer 2> /dev/null`)))
+    || file_exists($COMPOSER = rtrim((string) ('\\' === \DIRECTORY_SEPARATOR ? `git rev-parse --show-toplevel 2> NUL` : `git rev-parse --show-toplevel 2> /dev/null`)).\DIRECTORY_SEPARATOR.'composer.phar')
     ? ('#!/usr/bin/env php' === file_get_contents($COMPOSER, false, null, 0, 18) ? $PHP : '').' '.escapeshellarg($COMPOSER) // detect shell wrappers by looking at the shebang
     : 'composer';