Use is_string() rather than !== null for extra clarity, succinctl…

…y providing extra information.


Good suggestion.  I agree.  It's `null|string` (nothing else), so much clearer to test for the non-null type.

Co-authored-by: Oliver Klee <github@oliverklee.de>

src/CssInliner.php

@@ -492,7 +492,7 @@ private function getCssFromAllStyleNodes(): string
 
         $css = '';
         foreach ($styleNodes as $styleNode) {
-            if ($styleNode->nodeValue !== null) {
+            if (\is_string($styleNode->nodeValue)) {
                 $css .= "\n\n" . $styleNode->nodeValue;
             }
             $parentNode = $styleNode->parentNode;