Issue #3448572 by ptmkenny: Provide more detailed debug info when the test message fails

src/Form/FirebasePhpSendTestMessageForm.php

@@ -97,8 +97,10 @@ final class FirebasePhpSendTestMessageForm extends FormBase {
     // @phpstan-ignore-next-line Exception is shown to admin, so no rethrowing.
     catch (\Exception $e) {
       Error::logException($this->logger('firebase_php'), $e);
-      $this->messenger()->addError($this->t('Failed to send the test message. Error: %error', [
+      $details = method_exists($e, 'errors') ? $e->errors() : 'No details available.';
+      $this->messenger()->addError($this->t('Failed to send the test message. Error: %error More info: %errorDetails', [
         '%error' => $e->getMessage(),
+        '%errorDetails' => json_encode($details),
       ]));
     }
   }