Throw an exception if code coverage fails to write to disk

Author: duncan3dc

composer.json

@@ -31,6 +31,7 @@
     "require": {
         "php": "^7.3 || ^8.0",
         "ext-dom": "*",
+        "ext-libxml": "*",
         "ext-xmlwriter": "*",
         "nikic/php-parser": "^4.7",
         "phpunit/php-file-iterator": "^3.0.3",

src/Report/Xml/Facade.php

@@ -270,7 +270,24 @@ private function saveDocument(DOMDocument $document, string $name): void
         $document->preserveWhiteSpace = false;
         $this->initTargetDirectory(dirname($filename));
 
+        $original = \libxml_use_internal_errors(true);
+
         /* @see https://bugs.php.net/bug.php?id=79191 */
-        file_put_contents($filename, $document->saveXML());
+        $xml = $document->saveXML();
+
+        if ($xml === false) {
+            $message = 'Unable to generate the XML';
+
+            foreach (\libxml_get_errors() as $error) {
+                $message .= "\n" . $error->message;
+            }
+
+            throw new \RuntimeException($message);
+        }
+
+        \libxml_clear_errors();
+        \libxml_use_internal_errors($original);
+
+        \file_put_contents($filename, $xml);
     }
 }