Rule source on GitHub

DowngradeStreamIsattyRector

Downgrade stream_isatty() function

 class SomeClass
 {
     public function run($stream)
     {
-        $isStream = stream_isatty($stream);
+        $streamIsatty = function ($stream) {
+            if (\function_exists('stream_isatty')) {
+                return stream_isatty($stream);
+            }
+
+            if (!\is_resource($stream)) {
+                trigger_error('stream_isatty() expects parameter 1 to be resource, '.\gettype($stream).' given', \E_USER_WARNING);
+
+                return false;
+            }
+
+            if ('\\' === \DIRECTORY_SEPARATOR) {
+                $stat = @fstat($stream);
+                // Check if formatted mode is S_IFCHR
+                return $stat ? 0020000 === ($stat['mode'] & 0170000) : false;
+            }
+
+            return \function_exists('posix_isatty') && @posix_isatty($stream);
+        };
+        $isStream = $streamIsatty($stream);
     }
 }

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\DowngradePhp72\Rector\FuncCall\DowngradeStreamIsattyRector;

return RectorConfig::configure()
    ->withRules([
        DowngradeStreamIsattyRector::class,
    ]);