Strip CSS comments from <style> tags

src/Pattern/Style.php

@@ -8,6 +8,11 @@
 
 final class Style implements PatternInterface
 {
+    private const ZERO = 0;
+    private const CSS_COMMENT_OPEN = '<!--';
+    private const CSS_COMMENT_OPEN_LENGTH = 4;
+    private const CSS_COMMENT_CLOSE = '-->';
+
     /** @var CompressorInterface */
     private $compressor;
 
@@ -25,6 +30,7 @@ public function compress(SimpleHtmlDomInterface $element): void
     {
         /** @var string $innerHtml */
         $innerHtml = $element->innerhtml;
+        $innerHtml = $this->stripComments($innerHtml);
         $compressedInnerHtml = $this->compressor->compress($innerHtml);
 
         if ($compressedInnerHtml === '') {
@@ -37,4 +43,18 @@ public function compress(SimpleHtmlDomInterface $element): void
 
         $element->innerhtml = $compressedInnerHtml;
     }
+
+    private function stripComments(string $contents): string
+    {
+        if (\strpos($contents, self::CSS_COMMENT_OPEN) === self::ZERO) {
+            $contents = \substr($contents, self::CSS_COMMENT_OPEN_LENGTH);
+        }
+
+        $pos = \strpos($contents, self::CSS_COMMENT_CLOSE);
+        if ($pos !== false) {
+            $contents = \substr($contents, self::ZERO, $pos);
+        }
+
+        return $contents;
+    }
 }

tests/EdgeCases/css-wrapped-in-comments/in.html

@@ -0,0 +1,7 @@
+<style>
+    <!--
+h1 {
+    color: red;
+}
+-->
+</style>

tests/EdgeCases/css-wrapped-in-comments/out.html

@@ -0,0 +1 @@
+<style>h1{color:red}</style>